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 A385204 #11 Jun 22 2025 00:16:27 %S A385204 1,5,25,0,-1250,-6875,65625,1062500,0,-116796875,-782031250, %T A385204 8609375000,155390625000,0,-19950927734375,-141498046875000, %U A385204 1635108642578125,30759411621093750,0,-4223049316406250000,-30787073669433593750,364567847442626953125 %N A385204 G.f. A(x) satisfies A(x) = ( 1 + 25*x*A(x)^3 )^(1/5). %F A385204 a(n) = 25^n * binomial(3*n/5+1/5,n)/(3*n+1). %F A385204 G.f. A(x) satisfies A(x) = 1/A(-x*A(x)). %F A385204 G.f.: ( (1/x) * Series_Reversion(x/(1+25*x)^(3/5)) )^(1/3). %F A385204 a(5*n+3) = 0 for n >= 0. %F A385204 G.f.: 1/B(-x), where B(x) is the g.f. of A385203. %o A385204 (PARI) a(n) = 25^n*binomial(3*n/5+1/5, n)/(3*n+1); %Y A385204 Cf. A078534, A385203, A385205. %K A385204 sign %O A385204 0,2 %A A385204 _Seiichi Manyama_, Jun 21 2025