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%I #10 May 30 2023 12:01:10
%S 1,1,1,2,1,1,2,1,1,1,3,1,1,1,1,3,2,1,1,1,1,4,2,1,1,1,1,1,4,2,1,1,1,1,
%T 1,1,5,2,2,1,1,1,1,1,1,5,3,2,1,1,1,1,1,1,1,6,3,2,1,1,1,1,1,1,1,1,6,3,
%U 2,2,1,1,1,1,1,1,1,1,7,3,2,2,1,1,1,1,1,1,1,1,1,7,4,2,2,1,1,1,1,1,1,1,1,1,1
%N Triangle read by rows: A101688 * A051731.
%C More precisely, form the product of the lower triangular matrix T defined in A101688 and the lower triangular matrix T defined in A051731. - _N. J. A. Sloane_, Dec 05 2020
%C Row sums = A060831: (1, 2, 4, 5, 7, 9, 11, 12, 15,...).
%C A168509 = A051731 * A101688
%e First few rows of the triangle =
%e 1;
%e 1, 1;
%e 2, 1, 1;
%e 2, 1, 1, 1;
%e 3, 1, 1, 1, 1;
%e 3, 2, 1, 1, 1, 1;
%e 4, 2, 1, 1, 1, 1, 1;
%e 4, 2, 1, 1, 1, 1, 1, 1;
%e 5, 2, 2, 1, 1, 1, 1, 1, 1;
%e 5, 3, 2, 1, 1, 1, 1, 1, 1, 1;
%e 6, 3, 2, 1, 1, 1, 1, 1, 1, 1, 1;
%e 6, 3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1;
%e 7, 3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1;
%e 7, 4, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1;
%e 8, 4, 3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1;
%e 8, 4, 3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1;
%e 9, 4, 3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1;
%e ...
%Y Cf. A051731, A060831, A101688, A168509.
%K nonn,tabl
%O 1,4
%A _Gary W. Adamson_, Nov 27 2009
%E a(29) = 1 inserted and more terms from _Georg Fischer_, May 29 2023
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