This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A368889 #9 Jan 09 2024 08:45:47
%S A368889 1,1,9,55,4289,47376,10358713,162592977,70065589761,1419907258279,
%T A368889 1015035028009001,25173466118539344,26947505294538873409,
%U A368889 790057195504021692521,1183327797361056503499225,40027334070963910087734751,79925496016112851520801796097
%N A368889 a(n) = Sum_{k=0..floor(n/2)} n^(3*k) * binomial(n-k,k).
%F A368889 a(n) = [x^n] 1/(1 - x - n^3*x^2).
%F A368889 a(n) ~ n^(3*n/2) if n is even and a(n) ~ n^((3*n-1)/2)/2 if n is odd. - _Vaclav Kotesovec_, Jan 09 2024
%t A368889 Table[Hypergeometric2F1[1/2 - n/2, -n/2, -n, -4*n^3], {n, 0, 20}] (* _Vaclav Kotesovec_, Jan 09 2024 *)
%o A368889 (PARI) a(n) = sum(k=0, n\2, n^(3*k)*binomial(n-k, k));
%Y A368889 Cf. A171180, A368888.
%K A368889 nonn,easy
%O A368889 0,3
%A A368889 _Seiichi Manyama_, Jan 09 2024