A128187 - OEIS

%I #6 Apr 16 2013 05:46:31

%S 1,1,1,2,0,1,2,2,0,1,3,0,1,0,1,3,3,1,1,0,1,4,0,1,0,1,0,1,4,4,1,2,0,1,

%T 0,1,5,0,2,0,1,0,1,0,1,5,5,1,2,1,1,0,1,0,1,6,0,2,0,1,0,1,0,1,0,1,6,6,

%U 2,3,1,2,0,1,0,1,0,1,7,0,2,0,1,0,1,0,1,0,1,0,1,7,7,2,3,1,2,1,1

%N Matrix product A128174 * A051731 read by rows.

%F A128174 * A051731 as infinite lower triangular matrices.

%e First few rows of the triangle are:

%e 1;

%e 1, 1;

%e 2, 0, 1;

%e 2, 2, 0, 1;

%e 3, 0, 1, 0, 1;

%e 3, 3, 1, 1, 0, 1;

%e 4, 0, 1, 0, 1, 0, 1;

%e 4, 4, 1, 2, 0, 1, 0, 1;

%e ...

%p A128187 := proc(n,k)

%p     add( A128174(n,j)*A051731(j,k), j=k..n) ;

%p end proc: # _R. J. Mathar_, Apr 16 2013

%Y Cf. A128188 (row sums), A128174, A051731.

%K nonn,easy,tabl

%O 1,4

%A _Gary W. Adamson_, Mar 07 2007