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 A048505 #8 Mar 30 2012 18:56:55
%S A048505 1,2,1,7,5,1,25,18,10,1,81,56,35,17,1,241,160,101,58,26,1,673,432,269,
%T A048505 160,87,37,1,1793,1120,685,408,233,122,50,1,4609,2816,1693,1000,577,
%U A048505 320,163,65,1,11521,6912,4093,2392,1377,776,421
%N A048505 Array T read by diagonals, n-th difference of (T(k,n),T(k,n-1),...,T(k,0)) is (k+n)^2, for n=1,2,3,...; k=0,1,2,...
%F A048505 T(k, n) = (n^2 + (4k+1)n + (2k)^2) * 2^(n-2) - k^2 + 1. - _Ralf Stephan_, Feb 05 2004
%e A048505 Diagonals: {1}; {2,1}; {7,5,1}; ...
%Y A048505 Row 2 = (1, 5, 18, 56, 160, ...) = A001793.
%K A048505 nonn,tabl
%O A048505 0,2
%A A048505 _Clark Kimberling_