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 A048201 #8 Mar 30 2012 18:56:54
%S A048201 1,2,3,4,6,7,5,9,11,12,8,13,17,19,20,10,18,23,27,29,30,14,24,32,37,41,
%T A048201 43,44,15,29,39,47,52,56,58,59,16,31,45,55,63,68,72,74,75,21,37,52,66,
%U A048201 76,84,89,93,95,96,22,43,59,74,88,98,106,111
%N A048201 Triangular array T read by rows: T(i,j)=b(i+1)-b(i+1-j); j=1,2,...,i; i=1,2,3,...; b=A004978.
%F A048201 T(n, 1)=least number not in any preceding row and T(n, k)=T(n, 1)+T(n-1, 1)+...+T(n-k+1, 1) for k >= 2.
%e A048201 Rows: {1}, {2,3},{4,6,7}, ...
%Y A048201 T(n, 1)=c(n), where c=A002048.
%Y A048201 T(n, n)=d(n), where d=A002049.
%K A048201 nonn,tabl
%O A048201 1,2
%A A048201 _Clark Kimberling_