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 A143595 #2 Mar 30 2012 17:25:32 %S A143595 1,2,2,3,4,2,4,6,4,2,5,8,6,4,2,6,10,8,6,4,2,7,12,10,8,6,4,2,8,14,12, %T A143595 10,8,6,4,2,9,16,14,12,10,8,6,4,2,10,18,16,14,12,10,8,6,4,2,11,20,18, %U A143595 16,14,12,10,8,6,4,2 %N A143595 Triangle read by rows, A000012 * (an infinite lower triangular matrix with 1's in the first column and the rest 2's); 1<=k<=n. %C A143595 Row sums = n^2. %C A143595 The linear sequence A056944 is more appropriately a triangle, (reversal of A143595). %F A143595 Triangle read by rows, A000012 * (an infinite lower triangular matrix with 1's in the first column and the rest 2's); i.e. (1; 1,2; 1,2,2;...). A000012 = an infinite lower triangular matrix with all 1's. 1<=k<=n %e A143595 First few rows of the triangle = %e A143595 1; %e A143595 2, 2; %e A143595 3, 4, 2; %e A143595 4, 6, 4, 2; %e A143595 5, 8, 6, 4, 2; %e A143595 6, 10, 8, 6, 4, 2; %e A143595 7, 12, 10, 8, 6, 4, 2; %e A143595 ... %Y A143595 Cf. A056944. %K A143595 nonn,tabl %O A143595 1,2 %A A143595 _Gary W. Adamson_, Aug 26 2008