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 A215552 #18 Aug 29 2025 04:14:44
%S A215552 1,7,104,1748,31000,566618,10559208,199448964,3804949176,73143988775,
%T A215552 1414591812920,27492340515912,536480138597624,10504551860174120,
%U A215552 206284010045343000,4061109502392133464,80126310234711780600,1583953257985260802200,31365436013686385802048
%N A215552 a(n) = binomial(8*n,n)*(6*n+1)/(7*n+1).
%C A215552 Number of standard Young tableaux of shape [7n,n].
%H A215552 Alois P. Heinz, <a href="/A215552/b215552.txt">Table of n, a(n) for n = 0..235</a>
%H A215552 Wikipedia, <a href="https://en.wikipedia.org/wiki/Young_tableau">Young tableau</a>.
%F A215552 a(n) = C(8*n,n)*(6*n+1)/(7*n+1).
%F A215552 a(n) = [x^n] ((1 - sqrt(1 - 4*x))/(2*x))^(6*n+1). - _Ilya Gutkovskiy_, Nov 01 2017
%F A215552 a(n) ~ 3 * 4^(12*n+1) / (7^(7*n+3/2) * sqrt(Pi*n)). - _Amiram Eldar_, Aug 29 2025
%p A215552 a:= n-> binomial(8*n,n)*(6*n+1)/(7*n+1):
%p A215552 seq(a(n), n=0..20);
%t A215552 Table[Binomial[8n,n] (6n+1)/(7n+1),{n,0,20}] (* _Harvey P. Dale_, Mar 30 2014 *)
%Y A215552 Column k=7 of A214776.
%K A215552 nonn,changed
%O A215552 0,2
%A A215552 _Alois P. Heinz_, Aug 15 2012