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 A362999 #9 May 12 2023 15:57:38
%S A362999 2,3,15,105,315,3465,45045,9009,153153,14549535,14549535,19684665,
%T A362999 1673196525,5019589575,145568097675,4512611027925,4512611027925,
%U A362999 4512611027925,166966608033225,316824683175,6845630929362225,294362129962575675,294362129962575675,13835020108241056725
%N A362999 a(n) = denominator(R(2*n + 1, 2*n + 1, 1)) where R(n, k, x) = Sum_{u=0..k} ( Sum_{j=0..u} x^j * binomial(u, j) * (j + 1)^n ) / (u + 1).
%C A362999 See A363000 for a discussion of the polynomials.
%p A362999 # See A363000 for a program.
%Y A362999 Cf. A363001 (all denominators), A363000.
%K A362999 nonn,frac
%O A362999 0,1
%A A362999 _Peter Luschny_, May 12 2023