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 A162507 #5 Sep 28 2016 06:38:50 %S A162507 1,2,1,2,3,1,4,3,4,1,4,9,4,5,1,6,12,12,5,6,1,6,18,24,15,6,7,1,8,24,36, %T A162507 30,18,7,8,1,8,33,60,60,36,21,8,9,1,10,39,88,95,72,42,24,9,10,1,10,51, %U A162507 124,160,138,84,48,27,10,11 %N A162507 Triangle read by rows, finite differences of an array generated by an infinite product (Cf. A162506). %C A162507 Row sums = A162506 starting (1, 3, 6, 12, 23, 42, 77,...). %F A162507 Given the infinite product and array shown in A162506, we have %F A162507 a = [1,1,1,...], b = [1,0,2,0,2,0,2,...], c = [1,0,0,3,0,0,3,0,0,3,...]; %F A162507 The array is a, a*b, a*b*c,... Finite differences of array columns = rows of the triangle, deleting the first "1". %e A162507 The array = %e A162507 1,...1,...1,...1,...1,...; = a %e A162507 1,...1,...3,...3,...5,...; = a*b %e A162507 1,...1,...3,...6,...8,...; = a*b*c %e A162507 1,...1,...3,...6,..12,...; = a*b*c*d %e A162507 ... %e A162507 taking finite differences from the top, then discarding the first "1", %e A162507 we obtain triangle A162507: %e A162507 1; %e A162507 1, 2; %e A162507 1, 2, 3; %e A162507 1, 4, 3, 4; %e A162507 1, 4, 9, 4, 5; %e A162507 1, 6, 12, 12, 5, 6; %e A162507 1, 6, 18, 24, 15, 6, 7; %e A162507 1, 8, 24, 36, 30, 18, 7, 8; %e A162507 1, 8, 33, 60, 60, 36, 21, 8, 9; %e A162507 1, 10, 39, 88, 95, 72, 42, 24, 9, 10; %e A162507 1, 10, 51, 124, 160, 138, 84, 48, 27, 10, 11; %e A162507 ... %Y A162507 Cf. A162506. %K A162507 nonn,tabl %O A162507 2,2 %A A162507 _Gary W. Adamson_, Jul 04 2009