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 A127234 #7 May 08 2013 16:55:15
%S A127234 1,2,36,17280,435456000,941525544960000,257498348545415577600000,
%T A127234 12293098054744302855420641280000000,
%U A127234 134988938425519353794787639744975077376000000000,434085115076654530026451920435442716425635693068288000000000000
%N A127234 a(n) = n! (sum(1..n-1))!.
%C A127234 Number of distinct n x n symmetrical matrices containing A000217(n+1) different elements which have that same trace.
%t A127234 Table[n! (Sum[x, {x, 1, n-1}])!, {n, 1, 10}]
%t A127234 Table[n!((n(n-1))/2)!,{n,10}] (* _Harvey P. Dale_, May 08 2013 *)
%Y A127234 Cf. A127233, A127235.
%K A127234 nonn
%O A127234 1,2
%A A127234 _Artur Jasinski_, Jan 09 2007, Jan 11 2007
%E A127234 Edited by _Jason G. Wurtzel_, Oct 08 2010
%E A127234 Corrected and extended by _Harvey P. Dale_, May 08 2013