A135723 - OEIS

A135723

A122890 + A000012 - I, I = Identity matrix.

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, 1, 1, 2, 251, 1979, 2383, 429, 1, 1, 1, 1, 303, 6277, 19509, 12805, 1430, 1, 1, 1, 1, 299, 15675, 106493, 168609, 66947, 4862

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OFFSET

0,6

COMMENTS

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

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

LINKS

Table of n, a(n) for n=0..54.

FORMULA

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

EXAMPLE

First few rows of the triangle:

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

...

CROSSREFS

Cf. A122890, A005095, A000108.

Sequence in context: A213953 A000361 A246596 * A125311 A341359 A127568

Adjacent sequences: A135720 A135721 A135722 * A135724 A135725 A135726

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Nov 25 2007

STATUS

approved