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 A373577 #9 Jun 10 2024 10:02:16
%S A373577 1,1,1,10,37,136,1261,6616,45865,479872,3206521,31165696,356045581,
%T A373577 3082798720,37528974757,443190912256,4792765859281,69943918698496,
%U A373577 875123733523825,11059833224507392,179428023035501941,2557848382674927616,37699048392962570461
%N A373577 Expansion of e.g.f. exp(x * (1 + x^2)^(3/2)).
%F A373577 a(n) = n! * Sum_{k=0..floor(n/2)} binomial(3*n/2-3*k,k)/(n-2*k)!.
%F A373577 a(n) == 1 mod 9.
%o A373577 (PARI) a(n) = n!*sum(k=0, n\2, binomial(3*n/2-3*k, k)/(n-2*k)!);
%Y A373577 Cf. A118395, A190863, A373578.
%K A373577 nonn
%O A373577 0,4
%A A373577 _Seiichi Manyama_, Jun 10 2024