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 A381600 #7 Mar 01 2025 08:37:37 %S A381600 1,1,5,39,383,4360,55201,758877,11157081,173623407,2838995592, %T A381600 48515016273,862904739711,15923514065053,304089551295359, %U A381600 5997295071211547,121944040723497105,2552667957311169834,54944459391676448365,1214747696691087352576,27559533140410855702244 %N A381600 G.f. A(x) satisfies A(x) = 1/(1 - x * A(x)^2 * A(x*A(x)^2)^2). %F A381600 See A381592. %o A381600 (PARI) a(n, k=1) = if(k==0, 0^n, k*sum(j=0, n, binomial(2*n+j+k, j)/(2*n+j+k)*a(n-j, 2*j))); %Y A381600 Column k=1 of A381592. %Y A381600 Cf. A120971. %K A381600 nonn %O A381600 0,3 %A A381600 _Seiichi Manyama_, Mar 01 2025