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 A127233 #11 Aug 27 2021 11:10:43
%S A127233 1,1,12,4320,87091200,156920924160000,36785478363630796800000,
%T A127233 1536637256843037856927580160000000,
%U A127233 14998770936168817088309737749441675264000000000,43408511507665453002645192043544271642563569306828800000000000
%N A127233 a(n) = n!*(n*(n+1)/2)!.
%p A127233 seq(n!*(n*(n+1)/2)!,n=0..9); # _Emeric Deutsch_, Jan 20 2007
%t A127233 Table[n!((n(n+1))/2)!,{n,0,10}] (* _Harvey P. Dale_, Aug 27 2021 *)
%Y A127233 Cf. A127234, A127236.
%K A127233 nonn
%O A127233 0,3
%A A127233 _Artur Jasinski_, Jan 09 2007
%E A127233 More terms from _Emeric Deutsch_, Jan 20 2007