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 A334575 #15 May 18 2020 07:00:10 %S A334575 1,2,10,2002,52860229080,53570336911983273963270306331114400 %N A334575 a(n) = binomial(C(n+1),C(n)) where C(n) = A000108(n) the n-th Catalan number. %Y A334575 Cf. A000108, A058077, A066526, A080911. %K A334575 nonn %O A334575 0,2 %A A334575 _Henry Cryns_, May 06 2020