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 A368890 #8 Jan 09 2024 08:45:20
%S A368890 1,1,65,19737,16789505,30525391000,101570840860033,558574349855881107,
%T A368890 4722492584690006360065,58150612359276833311664895,
%U A368890 1000009000028000035000015000001,23225285520096132372224712190010064,708804486128121003209727133170234347521
%N A368890 a(n) = Sum_{k=0..floor(n/2)} n^(3*(n-2*k)) * binomial(n-k,k).
%F A368890 a(n) = [x^n] 1/(1 - n^3*x - x^2).
%F A368890 a(n) ~ n^(3*n). - _Vaclav Kotesovec_, Jan 09 2024
%t A368890 Join[{1}, Table[n^(3*n) * Hypergeometric2F1[1/2 - n/2, -n/2, -n, -4/n^6], {n, 1, 15}]] (* _Vaclav Kotesovec_, Jan 09 2024 *)
%o A368890 (PARI) a(n) = sum(k=0, n\2, n^(3*(n-2*k))*binomial(n-k, k));
%Y A368890 Cf. A084845, A176233.
%Y A368890 Cf. A368889.
%K A368890 nonn,easy
%O A368890 0,3
%A A368890 _Seiichi Manyama_, Jan 09 2024