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 A210951 #20 Mar 12 2015 23:22:52 %S A210951 1,0,2,0,0,3,0,0,1,5,0,0,0,1,7,0,0,0,1,3,11,0,0,0,0,1,3,15,0,0,0,0,1, %T A210951 3,6,22,0,0,0,0,0,1,4,7,30,0,0,0,0,0,1,3,7,11,42,0,0,0,0,0,0,1,4,9,13, %U A210951 56,0,0,0,0,0,0,1,3,8,15,20,77,0,0,0 %N A210951 Triangle read by rows: T(n,k) = number of parts in the k-th column of the shell model of partitions considering only the n-th shell and with its parts aligned to the right margin. %e A210951 For n = 6 and k = 1..6 the 6th shell looks like this: %e A210951 ------------------------- %e A210951 k: 1, 2, 3, 4, 5, 6 %e A210951 ------------------------- %e A210951 . 6 %e A210951 . 3 + 3 %e A210951 . 4 + 2 %e A210951 . 2 + 2 + 2 %e A210951 . 1 %e A210951 . 1 %e A210951 . 1 %e A210951 . 1 %e A210951 . 1 %e A210951 . 1 %e A210951 . 1 %e A210951 . %e A210951 The total number of parts in columns 1-6 are %e A210951 . 0, 0, 0, 1, 3, 11, the same as the 6th row of triangle. %e A210951 Triangle begins: %e A210951 1; %e A210951 0, 2; %e A210951 0, 0, 3; %e A210951 0, 0, 1, 5; %e A210951 0, 0, 0, 1, 7; %e A210951 0, 0, 0, 1, 3, 11; %e A210951 0, 0, 0, 0, 1, 3, 15; %e A210951 0, 0, 0, 0, 1, 3, 6, 22; %e A210951 0, 0, 0, 0, 0, 1, 4, 7, 30; %e A210951 0, 0, 0, 0, 0, 1, 3, 7, 11, 42; %e A210951 0, 0, 0, 0, 0, 0, 1, 4, 9, 13, 56; %e A210951 0, 0, 0, 0, 0, 0, 1, 3, 8, 15, 20, 77; %Y A210951 Row sums give A138137. Column sums converge to A000070. Right border gives A000041, n >= 1. %Y A210951 Cf. A135010, A138121, A194714, A210945, A210950, A210952, A210953. %K A210951 nonn,tabl %O A210951 1,3 %A A210951 _Omar E. Pol_, Apr 22 2012