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 A174995 #5 Nov 21 2013 12:50:01 %S A174995 0,1,2,3,4,5,6,7,8,9,10,12,14,15,16,18,20,21,24,25,27,28,30,32,35,36, %T A174995 40,42,45,48,49,54,56,63,64,72,81 %N A174995 Products of decimal digits. %C A174995 Apart from the initial zero: finite subset of A002473 with 37 elements: a(37)=81=9*9; %C A174995 a(n) = A079904(j,i) for certain i,j with 0<=i<=j<=9. %t A174995 Union[Times@@@Tuples[Range[0,9],2]] (* _Harvey P. Dale_, Oct 08 2011 *) %K A174995 base,fini,full,nonn %O A174995 1,3 %A A174995 _Reinhard Zumkeller_, Apr 03 2010, Apr 05 2010