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 A104253 #16 Apr 03 2021 02:46:36
%S A104253 1,3,6,11,21,45,113,339,1221,5273,27237,167985,1235820,10838397,
%T A104253 113281002,1410702627,20928310905,369834091857,7784253038081,
%U A104253 195135698311989,5825657474768916,207120610510791805,8769156584345509398,442116458092151729925,26542966216935028587896
%N A104253 Row sums of triangle in A116925.
%H A104253 Seiichi Manyama, <a href="/A104253/b104253.txt">Table of n, a(n) for n = 0..162</a>
%F A104253 a(n) ~ c * BarnesG(n/3 + 1)^3 * BarnesG(n+1) / BarnesG(2*n/3 + 1)^3 ~ c * exp(1/12) * 3^(n^2/2) / (A * n^(1/12) * 2^(2*n^2/3 - 1/4)), where c = 5.2335188744705752675068634418929940491557563366762252523140713171090086689943... and A is the Glaisher-Kinkelin constant A074962. - _Vaclav Kotesovec_, Apr 02 2021
%t A104253 Table[Sum[1 + Sum[Product[Binomial[n-1, n - s + j]/Binomial[n-1, j], {j, 0, k-1}], {k, 1, s}], {s, 0, n}], {n, 0, 25}] (* _Vaclav Kotesovec_, Apr 02 2021 *)
%t A104253 Table[BarnesG[1 + n] * Sum[BarnesG[1 + k] * BarnesG[1 + n - s] * BarnesG[1 - k + s] / (BarnesG[1 - k + n] * BarnesG[1 + k + n - s] * BarnesG[1 + s]), {s, 0, n}, {k, 0, s}], {n, 0, 20}] (* _Vaclav Kotesovec_, Apr 02 2021 *)
%Y A104253 Cf. A116925.
%K A104253 nonn
%O A104253 0,2
%A A104253 _N. J. A. Sloane_, Sep 08 2006