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 A152906 #3 Sep 08 2013 13:31:32
%S A152906 1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,1,1,1,1,1,1,3,3,3,3,3,3,1,1,1,1,1,1,4,
%T A152906 4,4,6,6,6,4,4,4,1,1,1,1,1,1,5,5,5,10,10,10,10,10,10,5,5,5,1,1,1,1,1,
%U A152906 1,6,6,6,15,15,15,20,20,20,15,15,15,6,6,6,1,1,1,1,1,1,7,7,7,21,21,21,35,35
%N A152906 Irregular triangle read by rows, numbers in A007318 repeated three times .
%C A152906 Diagonal sums : A078467 .
%F A152906 Sum_{k, 0<=k<=2n}T(n,k)=3*2^(n).
%e A152906 Triangle begins : 1,1,1 ; 1,1,1,1,1,1 ; 1,1,1,2,2,2,1,1,1 ; 1,1,1,3,3,3,3,3,3,1,1,1, ; 1,1,1,4,4,4,6,6,6,4,4,4,1,1,1 ; 1,1,1,5,5,5,10,10,10,10,10,10,5,5,5,1,1,1 ; ...
%Y A152906 Cf. A007318, A152905
%K A152906 nonn,tabf
%O A152906 0,13
%A A152906 _Philippe Deléham_, Dec 14 2008