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 A381916 #12 Mar 10 2025 09:43:02
%S A381916 1,4,29,270,2897,34051,426199,5582619,75660075,1052748518,14956346820,
%T A381916 216088986290,3165555750458,46912569559556,702072705679590,
%U A381916 10595488626535181,161071258091631337,2464201011094137000,37911236702465987337,586166246311185676045,9103432675706477369934
%N A381916 Expansion of (1/x) * Series_Reversion( x * (1-x)^3 / B(x) ), where B(x) is the g.f. of A002293.
%F A381916 G.f. A(x) satisfies A(x) = B(x*A(x)) / (1 - x*A(x))^3.
%F A381916 a(n) = Sum_{k=0..n} binomial(n+4*k+1,k) * binomial(4*n-k+2,n-k)/(n+4*k+1).
%o A381916 (PARI) a(n) = sum(k=0, n, binomial(n+4*k+1, k)*binomial(4*n-k+2, n-k)/(n+4*k+1));
%Y A381916 Cf. A381914, A381915.
%Y A381916 Cf. A381880, A381913.
%Y A381916 Cf. A002293.
%K A381916 nonn
%O A381916 0,2
%A A381916 _Seiichi Manyama_, Mar 10 2025