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 A128228 #9 Jun 10 2017 16:43:58
%S A128228 1,2,2,3,6,3,4,8,12,4,5,10,15,20,5,6,12,18,24,30,6,7,14,21,28,35,42,7,
%T A128228 8,16,24,32,40,48,56,8,9,18,27,36,45,54,63,72,9,10,20,30,40,50,60,70,
%U A128228 80,90,10
%N A128228 A128229 * A002260.
%C A128228 Row sums = A006000: (1, 4, 12, 28, 55, 96, 154,...).
%F A128228 A128229 * A002260 as infinite lower triangular matrices.
%F A128228 Triangle, n * (each term of A128227).
%F A128228 T(n,k) = k*n if 1<=k<n, and T(n,n) = n. - _Hartmut F. W. Hoft_, Jun 10 2017
%e A128228 First few rows of the triangle are:
%e A128228 1;
%e A128228 2, 2;
%e A128228 3, 6, 3;
%e A128228 4, 8, 12, 4;
%e A128228 5, 10, 15, 20, 5;
%e A128228 6, 12, 18, 24, 30, 6;
%e A128228 7, 14, 21, 28, 35, 42, 7;
%e A128228 ...
%t A128228 (* first n rows of the triangle *)
%t A128228 a128228[n_] := Table[If[r==q, r, q r], {r, 1, n}, {q, 1, r}]
%t A128228 Flatten[a128228[10]] (* data *)
%t A128228 TableForm[a128228[7]] (* triangle *)
%t A128228 (* _Hartmut F. W. Hoft_, Jun 10 2017 *)
%Y A128228 Cf. A128229, A002260, A006000, A128227.
%K A128228 nonn,tabl
%O A128228 1,2
%A A128228 _Gary W. Adamson_, Feb 19 2007