This is a question with a pretty broad scope, so let me preface everything I'm going to say with a few nuances and note that my response will inevitably be contentious and debated.

First, we have to define what we mean by Africa. Africa is a huge continent with a lot of different subcultures, which are all different and have all been impacted differently by the United States and its broader culture, as well as African American culture. It's also important to note that not all Africans are Black. However, even amongst Black Africans, the response you'd get on this question would be extremely different if you spoke of African American cultural influence on Liberia than African American cultural influence on Somalia. Many of the African American leaders who supported Pan-Africanism were focused on West Africa, so that's where I'll say we should focus.

Second, whose African American culture? African Americans are not a monolithic group, and there's a lot of variety in ideas and beliefs. For example, what is commonly called the Atlanta Compromise, initially supported by Booker T. Washington and W.E.B Du Bois, was controversial within the Black community. Because you asked specifically about Pan-Africanism, I think it would make sense to focus on notable African Americans who involved themselves in that movement. Just for simplicity, I'll name a few: John Henrik Clarke, Molefi Kete Asante, and to some extent, Maya Angelou. However, it should be noted that these individuals are by no means representative of the African American community as a whole. Being prominent, by definition, means to be to separated to some extent from the problems of the broader community. One of the reasons I've included Angelou is because she isn't typically grouped in the same category with the others, yet she did live in Africa and had an impact as an African American public intellectual.

The people I've chosen to name lead to the third problem: when? The impact of African American culture on African nations in the 1960s is very different from the impact that it had in the late 20th century and early 2000s. By focusing on these three people, I am centralizing our dialogue in the mid-20th century, but I should note that you would get a different answer if you were to focus on the impact in later years. One major example is the influence that Hip Hop has had on Afro-Pop. This is significant, but it isn't necessarily a consequence of pan-Africanism and all of the people I've mentioned as being prominent African American supporters of pan-Africanism pre-dated the rise and popularity of Hip Hop (or at least the zenith of their careers predated it). Furthermore, a lot of the most interesting influence has occurred in the last 20 years, which is outside the scope of this subreddit.

Fourth, there is the issue of what is meant by 'culture.' Do you mean beliefs, worldview, religion, music, dance, language, politics, family associations, economy, or all of the above? Along with that, the ideas of African and African American intellectuals can sometimes be different than that of the community at large. Intellectual culture is not always the same as the broader culture. But because we are discussing Pan-Africanism, intellectual culture is probably going to be the most relevant. Again, this is a pretty broad question so let me narrow down on what I think is most relevant and interesting and feel free to follow up.

Fifth, and most frustratingly, there is the issue of sources. As you mentioned, there is a lot written by African Americans on their thoughts on Africa, but not much on what Africans themselves thought. There actually has been much more written on this, but unfortunately most if it has been in the past 20 years (Chimamanda Ngozi Adichie is a Nigerian novelist who deals with the rift between Africans and African Americans in much of her work. Another prominent voice is Yaa Gyasi, whose ancestry is African, but was raised in the US). One solution to this issue is to do what historians do when it comes to slaves: read what the authors say that those we are focusing on said.

For simplicity's sake, I will focus on Ghana, as that is where Angelou and Asante had their most significant African experiences, and it is where Kwame Anthony Appiah, one of the most well-known critics of Afrocentrism, was raised. Du Bois himself settled in Ghana at the end of his life and is buried there. Ghana was also one of the primary sources of slaves during the slave trade, so it is often seen as a "homeland" by some African Americans. In a 1964 speech at the University of Ghana, Malcom X said:

I don’t feel that I am a visitor in Ghana or in any part of Africa. I feel that I am at home. I’ve been away for four hundred years, but not of my own volition, not of my own will.

Later in this same speech he praised President Kwame Nkrumah:

President Nkrumah is doing something there that the government in America does not like to see done, and that is he’s restoring the African image. He is making the African proud of the African image; and whenever the African becomes proud of the African image and this positive image is projected abroad, then the Black man in America, who up to now has had nothing but a negative image of Africa — automatically the image that the Black man in America has of his African brothers changes from negative to positive, and the image that the Black man in America has of himself will also change from negative to positive.

Yet, Malcom X was not initially invited to meet with Kwame Nkrumah. In a nation so recently independent, Nkrumah was trying to walk a fine line between doing what was in line with his role as a freedom fighter and the realpolitik of working with Britain and the US, who viewed Malcom X as a dissident troublemaker. Nkrumah eventually granted a meeting with Malcom, after which his traveling companions said he seemed especially somber. Kojo Botsio, Nkrumah's foreign minister said later:

We don't like what's being done to the African Americans, but it doesn't seem wise to raise, say, that sort of thing in the United Nations.

Nkrumah had specifically invited many African American expatriates to live in Ghana. He was the one who had granted Du Bois citizenship. He granted many of these expatriates roles as government officials. Part of this was ideological: it was evidence that Black people could run things, no matter what. However, there were also practical considerations. Ghana was a founding member of the Non-Aligned movement during the Cold War, and Nkrumah saw the influence and skill of African Americans as a way to gain international connections without taking a stance in support of the US, since by inviting them and hiring them to work for Ghana's government, he was still criticizing US policy. It was a way to refrain from taking a stance while still reaping some of the benefits taking a stance would have given him.

This rising of the ranks of African American intellectuals did lead to some resentment, but according to Angelou, the biggest African attitude towards them was indifference. She recounts:

We have tolerated a lot to be ignored...they're not mean, never mean, just a little distant for the most part...Our inability to speak their language obviously poses a problem. Without a common language, it’s very difficult to communicate.

Angelou eventually learned Fanti, but this of course took time. US agencies, such as USAID and the Peace Corps, were also present in Ghana at this time, which Angelou writes both Africans and African Americans avoided because the white officials within those agencies often treated both groups the way colonizers had treated Ghanaians in the past. However, it is possible that the rise of African Americans into official positions led to conflation of the agencies in the minds of some Ghanaians, and contributed to resentment towards them. As in many other African nations, the Peace Corps was seen by some as a cover for the CIA, and this eventually extended into a perception that the African American expatriate community was also secretly working for the CIA.

Coming in late behind u/q203, a different way to come at this question is to look at recirculations of African-American culture in African cultures since the 19th Century. And that's complicated not just because of reasons of scale and scope, as u/q203 notes, but also because you have to separate out three different kinds of influence:

1. Where the idea of African-American culture or life as heard or interpreted by Africans (often indirect chains of informational dissemination, such as newspapers) was important and influential to Africans but where there was also some degree of misrecognition involved. Robert T. Vinson's 2012 book The Americans Are Coming! The Dream of African-American Liberation in Segregationist South Africa is a great analysis of this kind of influence. Some of the influence he describes was based on direct interactions between African-Americans and South Africans but some of it was about a kind of millennarian dream or fantasy that Black Americans would come as an army to the rescue of their South African brothers. Figures like Joe Louis also sometimes featured in these sort of hopeful, quasi-religious visions.
2. Where African-American and African cultures mutually influenced each other indirectly through music, art and other kinds of cultural productions without direct interactions between the artists and performers themselves. E.g., the way that recordings travelled the Atlantic (in both directions), were listened to by musicians and audiences on the other side of that circuit, and where those musicians then incorporated what they heard into their own compositions and performances. There's a huge literature on these kinds of interactions across the entire 20th Century, focused on musical genres like soukous/zouk, hip-hop, jazz, reggae, etc. and also on centrally important African performers like Franco, Fela, Abdullah Ibrahim (Dollar Brand) and others. Musical albums like the collection From Marabi to Disco can give you a really vivid picture of how important African-American musical culture was to shaping South African musical culture (and often African stylings and performances were important similarly in the Americas over the same time period).
3. Through direct political and cultural interactions of the kind u/q203 is describing in their answer. Sometimes that involved people who specifically went with the hope of influencing a specific African country (and of being influenced by it); if you wanted to extend how complicated that turned out to be in the 1960s and 1970s in Ghana, you could read Kevin Gaines' excellent monograph African-Americans in Ghana; Saidiya Hartman's more recent history/travel narrative Lose Your Mother offers a depressing coda to that historical moment. There's also a kind of influence through direct presence that African-Americans have sometimes had that was more accidental or less instrumental. Muhammad Ali didn't necessarily have a specific intent in agreeing to the famous "Rumble in the Jungle" fight in Congo that is covered in the documentary When We Were Kings, but he (and Foreman and Don King) had some kind of "influence" as a result. u/q203 describes the impact that some Africans who have grown up substantially or entirely in the United States, Canada or Europe have had culturally when they have returned to reside and produce cultural work in their countries of origin, and it's a pretty complicated and contradictory impact in both directions, though often very generative and positive.