cp's OEIS Frontend

A168508 Triangle read by rows: A101688 * A051731.

%I A168508 #10 May 30 2023 12:01:10
%S A168508 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 A168508 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 A168508 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 A168508 Triangle read by rows: A101688 * A051731.
%C A168508 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 A168508 Row sums = A060831: (1, 2, 4, 5, 7, 9, 11, 12, 15,...).
%C A168508 A168509 = A051731 * A101688
%e A168508 First few rows of the triangle =
%e A168508 1;
%e A168508 1, 1;
%e A168508 2, 1, 1;
%e A168508 2, 1, 1, 1;
%e A168508 3, 1, 1, 1, 1;
%e A168508 3, 2, 1, 1, 1, 1;
%e A168508 4, 2, 1, 1, 1, 1, 1;
%e A168508 4, 2, 1, 1, 1, 1, 1, 1;
%e A168508 5, 2, 2, 1, 1, 1, 1, 1, 1;
%e A168508 5, 3, 2, 1, 1, 1, 1, 1, 1, 1;
%e A168508 6, 3, 2, 1, 1, 1, 1, 1, 1, 1, 1;
%e A168508 6, 3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1;
%e A168508 7, 3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1;
%e A168508 7, 4, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1;
%e A168508 8, 4, 3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1;
%e A168508 8, 4, 3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1;
%e A168508 9, 4, 3, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1;
%e A168508 ...
%Y A168508 Cf. A051731, A060831, A101688, A168509.
%K A168508 nonn,tabl
%O A168508 1,4
%A A168508 _Gary W. Adamson_, Nov 27 2009
%E A168508 a(29) = 1 inserted and more terms from _Georg Fischer_, May 29 2023