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 A381937 #11 Mar 11 2025 07:53:44
%S A381937 1,2,6,35,240,1805,14386,119365,1020136,8918423,79380514,716911887,
%T A381937 6553219720,60513355786,563648995020,5289485238552,49963186247220,
%U A381937 474655663418546,4532279676629700,43473774550929628,418706702628897708,4047555977981218963
%N A381937 G.f. A(x) satisfies A(x) = (1 + x) * B(x*A(x)), where B(x) is the g.f. of A001764.
%F A381937 a(n) = Sum_{k=0..n} binomial(4*k+1,k) * binomial(k+1,n-k)/(4*k+1).
%F A381937 a(n) = A365178(n) + A365178(n-1).
%o A381937 (PARI) a(n) = sum(k=0, n, binomial(4*k+1, k)*binomial(k+1, n-k)/(4*k+1));
%Y A381937 Cf. A025227, A381787, A381940.
%Y A381937 Cf. A001764, A346646, A365178.
%K A381937 nonn
%O A381937 0,2
%A A381937 _Seiichi Manyama_, Mar 10 2025