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 A101821 #4 Mar 30 2012 18:57:06
%S A101821 2,3,42,4,180,600,5,620,5400,7800,6,1890,36120,126000,100800,7,5534,
%T A101821 202860,1428840,2646000,1340640,8,14280,1016400,13053600,46710720,
%U A101821 53343360,18627840,9,36792,4702320,103133520,642978000,1380576960
%N A101821 Triangle read by rows: T(n,h) = number of functions f:{1,2,...,n}->{1,2,...,n-2} such that |Image(f)|=h, h=1,2,...,n-2; n=3,4,....
%F A101821 T(n, h) = C(n-2, h)*U(n, h), where U(n, h) is the array in A019538.
%e A101821 First rows:
%e A101821 2
%e A101821 3 42
%e A101821 4 180 600
%e A101821 5 620 5400 7800
%Y A101821 Cf. A019538, A101817, A101819.
%K A101821 nonn,tabl
%O A101821 0,1
%A A101821 _Clark Kimberling_, Dec 17 2004