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 A366405 #10 Oct 09 2023 11:20:15
%S A366405 1,2,-3,22,-138,1012,-7839,63506,-531024,4549276,-39723484,352237844,
%T A366405 -3163252976,28711196184,-262964888021,2427319896584,-22557930343459,
%U A366405 210889624536396,-1981972609174109,18714482015314016,-177453862702083994,1689045253793239952
%N A366405 G.f. A(x) satisfies A(x) = (1 + x / A(x)^(5/2)) / (1 - x).
%F A366405 a(n) = (-1)^(n-1) * Sum_{k=0..n} binomial(7*k/2-1,k) * binomial(5*k/2-1,n-k) / (7*k/2-1).
%o A366405 (PARI) a(n) = (-1)^(n-1)*sum(k=0, n, binomial(7*k/2-1, k)*binomial(5*k/2-1, n-k)/(7*k/2-1));
%Y A366405 Cf. A366400, A366401, A366402, A366403, A366404, A366406, A366407.
%K A366405 sign
%O A366405 0,2
%A A366405 _Seiichi Manyama_, Oct 09 2023