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 A371581 #17 Mar 29 2024 15:21:31
%S A371581 1,2,13,108,1018,10352,110724,1227752,13986369,162708728,1924866345,
%T A371581 23085868814,280060995369,3430479393210,42369377446083,
%U A371581 527064922683286,6597825455023465,83050276697808472,1050551595788997356,13347641275527720048,170259412138463630535
%N A371581 G.f. satisfies A(x) = ( 1 + x*A(x)^(5/2) / (1 - x*A(x)) )^2.
%F A371581 If g.f. satisfies A(x) = ( 1 + x*A(x)^(t/r) / (1 - x*A(x)^(u/r))^s )^r, then a(n) = r * Sum_{k=0..n} binomial(t*k+u*(n-k)+r,k) * binomial(n+(s-1)*k-1,n-k)/(t*k+u*(n-k)+r).
%F A371581 G.f.: A(x) = B(x)^2 where B(x) is the g.f. of A365192.
%o A371581 (PARI) a(n, r=2, s=1, t=5, u=2) = r*sum(k=0, n, binomial(t*k+u*(n-k)+r, k)*binomial(n+(s-1)*k-1, n-k)/(t*k+u*(n-k)+r));
%Y A371581 Cf. A006013, A211789, A365146, A371582.
%Y A371581 Cf. A371574, A365192.
%K A371581 nonn
%O A371581 0,2
%A A371581 _Seiichi Manyama_, Mar 28 2024