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