A140737 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A140737

Triangle read by rows, X^n * [1,0,0,0,...]; where X = an infinite tridiagonal matrix with (1,1,1,...) in the main and subdiagonals and (1,0,1,0,1,...) in the subsubdiagonal.

1, 1, 1, 1, 1, 2, 3, 1, 1, 1, 3, 6, 4, 5, 1, 1, 1, 4, 10, 10, 15, 6, 7, 1, 1, 1, 5, 15, 20, 35, 21, 28, 8, 9, 1, 1, 1, 6, 21, 35, 70, 56, 84, 36, 45, 10, 11, 1, 1, 1, 7, 28, 56, 126, 126, 210, 120, 165, 55, 66, 12, 13, 1, 1

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,6

LINKS

Table of n, a(n) for n=1..64.

EXAMPLE

First few rows of the triangle are:

1, 1, 1;

1, 2, 3, 1, 1;

1, 3, 6, 4, 5, 1, 1;

1, 4, 10, 10, 15, 6, 7, 1, 1;

1, 5, 15, 20, 35, 21, 28, 8, 9, 1, 1;