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 A137853 #2 Mar 31 2012 14:45:10 %S A137853 1,0,2,1,2,0,1,0,3,0,0,2,3,0,0,1,2,3,0,0,0,1,2,0,4,0,0,0,1,0,3,4,0,0, %T A137853 0,0,0,2,3,4,0,0,0,0,0,1,2,3,4,0,0,0,0,0,0,1,2,3,0,5,0,0,0,0,0,0,1,2, %U A137853 0,4,5,0,0,0,0,0,0,0,1,0,3,4,5,0,0,0,0,0,0,0,0,0,2,3,4,5,0,0,0,0,0,0,0,0,0 %N A137853 Triangle read by rows: row sums give natural numbers A000027. %C A137853 Each row contains a series of consecutive numbers. There is a diagonal pattern of zeros in the left part of the table. %e A137853 1 = 1 %e A137853 0+2 = 2 %e A137853 1+2+0 = 3 %e A137853 1+0+3+0 = 4 %e A137853 0+2+3+0+0 = 5 %e A137853 1+2+3+0+0+0 = 6 %e A137853 1+2+0+4+0+0+0 = 7 %e A137853 1+0+3+4+0+0+0+0 = 8 %e A137853 0+2+3+4+0+0+0+0+0 = 9 %Y A137853 Cf. A000027. %K A137853 nonn,tabl %O A137853 1,3 %A A137853 _Mats Granvik_, Feb 14 2008