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 A381945 #10 Mar 11 2025 08:03:18
%S A381945 1,3,12,79,695,6961,74679,837336,9689234,114822820,1386402276,
%T A381945 16994276781,210919650044,2645218761934,33470438908615,
%U A381945 426758782807956,5477657372957314,70720821402587371,917801926609131194,11966203939448781600,156662012236067711036,2058709975008385135863
%N A381945 G.f. A(x) satisfies A(x) = B(x*A(x)) / (1 - x)^2, where B(x) is the g.f. of A002293.
%F A381945 a(n) = Sum_{k=0..n} binomial(5*k+1,k) * binomial(n+k+1,n-k)/(5*k+1).
%o A381945 (PARI) a(n) = sum(k=0, n, binomial(5*k+1, k)*binomial(n+k+1, n-k)/(5*k+1));
%Y A381945 Cf. A086616, A381867, A381943.
%Y A381945 Cf. A002293.
%K A381945 nonn
%O A381945 0,2
%A A381945 _Seiichi Manyama_, Mar 10 2025