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 A126447 #5 Apr 22 2022 12:23:28
%S A126447 1,3,36,969,46376,3478761,377447148,56017460733,10912535409348,
%T A126447 2703343379981793,830496702831140346,310006778438284515093,
%U A126447 138247735223480364826280,72613463426660610635960445
%N A126447 Column 1 of triangle A126445; a(n) = C( C(n+3,3) - 1, n).
%t A126447 Table[Binomial[Binomial[n+3,3]-1,n],{n,0,20}] (* _Harvey P. Dale_, Apr 22 2022 *)
%o A126447 (PARI) a(n)=binomial((n+1)*(n+2)*(n+3)/3!-1, n)
%Y A126447 Cf. A126445; A126446, A126448, A126449; A126452, A126456, A126459.
%K A126447 nonn
%O A126447 0,2
%A A126447 _Paul D. Hanna_, Dec 27 2006