login
A122890 + A000012 - I, I = Identity matrix.
2

%I #6 Mar 27 2022 23:29:32

%S 1,1,1,1,1,2,1,1,2,5,1,1,1,11,14,1,1,1,9,71,42,1,1,1,5,161,425,132,1,

%T 1,1,2,251,1979,2383,429,1,1,1,1,303,6277,19509,12805,1430,1,1,1,1,

%U 299,15675,106493,168609,66947,4862

%N A122890 + A000012 - I, I = Identity matrix.

%C Row sums = A005095: (1, 2, 4, 9, 28, 125, 726, ...).

%C Main diagonal = A000108, the Catalan numbers: (1, 1, 2, 5, 14, 42, 132, ...).

%F A122890 + A000012 - Identity matrix; as infinite lower triangular matrices.

%e First few rows of the triangle:

%e 1;

%e 1, 1;

%e 1, 1, 2;

%e 1, 1, 2, 5;

%e 1, 1, 1, 11, 14;

%e 1, 1, 1, 9, 71, 42;

%e 1, 1, 1, 5, 161, 425, 132;

%e 1, 1, 1, 2, 251, 1979, 2383, 429;

%e ...

%Y Cf. A122890, A005095, A000108.

%K nonn,tabl

%O 0,6

%A _Gary W. Adamson_, Nov 25 2007