%I #4 Apr 05 2012 18:14:47
%S 1,3,2,5,4,2,7,6,4,2,9,8,6,4,2,11,10,8,6,4,2,13,12,10,8,6,4,2,15,14,
%T 12,10,8,6,4,2,17,16,14,12,10,8,6,4,2,19,18,16,14,12,10,8,6,4,2,21,20,
%U 18,16,14,12,10,8,6,4,2
%N Triangle read by rows, A000012 * A136521 * A000012; 1<=k<=n.
%C Row sums = A028387: (1, 5, 11, 19, 29, 41,...)
%F Triangle read by rows, A000012 * A136521 * A000012; 1<=k<=n. A136521 = an infinite lower triangular matrix with (1,2,2,2,...) in the main diagonal the rest zeros.
%e First few rows of the triangle =
%e 1;
%e 3, 2;
%e 5, 4, 2;
%e 7, 6, 4, 2;
%e 9, 8, 6, 4, 2;
%e 11, 10, 8, 6, 4, 2;
%e 13, 12, 10, 8, 6, 4, 2;
%e 15, 14, 12, 10, 8, 6, 4, 2;
%e ...
%Y Cf. A136521, A028387.
%K nonn,tabl
%O 1,2
%A _Gary W. Adamson_ & _Roger L. Bagula_, Aug 26 2008
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