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 A121909 #4 Sep 08 2013 13:30:54
%S A121909 1,2,3,10,29,162,799
%N A121909 S-D transform of factorial numbers A000142.
%F A121909 a(n)=Sum{k, 0<=k<=n}A051159(n,k)*A000142(k).
%e A121909 Row 1 : 1, 1, 2, 6, 24, 120, ...(A000142)
%e A121909 Row 2 : 1+1=2, 2-1=1, 6+2=8, 24-6=18, 120+24=144, ...
%e A121909 Row 3 : 1+2=3, 9-1=7, 18+8=26, 144-18=126, ...
%e A121909 Row 4 : 7+3=10, 26-7=19, 126+26=152, ...
%e A121909 Row 5 : 19+10=29, 152-19=133, ...
%e A121909 Row 6 : 133+29=162, ...
%e A121909 First term of each row form this sequence.
%K A121909 nonn
%O A121909 0,2
%A A121909 _Philippe Deléham_, Sep 01 2006