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 A130211 #6 Aug 06 2016 17:02:10 %S A130211 1,2,1,3,2,2,4,3,2,2,5,4,4,4,4,6,5,4,2,2,2,7,6,6,6,6,6,6,8,7,6,6,4,4, %T A130211 4,4,9,8,8,6,6,6,6,6,6,10,9,8,8,8,4,4,4,4,4,11,10,10,10,10,10,10,10, %U A130211 10,10,10,12,11,10,8,6,6,4,4,4,4,4,4,13,12,12,12,12,12,12,12,12 %N A130211 Triangle read by rows: matrix product A054522 * A000012. %F A130211 A054522 * A000012 as infinite lower triangular matrices. %F A130211 T(n,n) = A000010(n). %e A130211 First few rows of the triangle are: %e A130211 1; %e A130211 2, 1; %e A130211 3, 2, 2; %e A130211 4, 3, 2, 2; %e A130211 5, 4, 4, 4, 4; %e A130211 6, 5, 4, 2, 2, 2; %e A130211 7, 6, 6, 6, 6, 6, 6; %e A130211 8, 7, 6, 6, 4, 4, 4, 4; %e A130211 ... %p A130211 A130211 := proc(n,k) %p A130211 add( A054522(n,j),j=k..n) ; %p A130211 end proc: %p A130211 seq(seq(A130211(n,k),k=1..n),n=1..15) ; # _R. J. Mathar_, Aug 06 2016 %Y A130211 Cf. A000010, A054522, A130212 (product with swapped order), A057660 (row sums). %K A130211 nonn,tabl,easy %O A130211 1,2 %A A130211 _Gary W. Adamson_, May 17 2007