A137639 - OEIS

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A137639

Triangle read by rows, A026794 * A051731.

1, 2, 1, 3, 0, 1, 5, 2, 0, 1, 7, 1, 0, 0, 1, 11, 3, 2, 0, 0, 1, 15, 2, 1, 0, 0, 0, 1, 22, 6, 1, 2, 0, 0, 0, 1, 30, 5, 3, 1, 0, 0, 0, 0, 1, 42, 9, 2, 1, 2, 0, 0, 0, 0, 1, 56, 9, 3, 1, 1, 0, 0, 0, 0, 0, 1, 77, 16, 6, 3, 1, 2, 0, 0, 0, 0, 0, 1

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OFFSET

1,2

COMMENTS

Left border = A000041 starting with offset 1: (1, 2, 3, 5, 7, 11, 15, ...).

Row sums = A137640: (1, 3, 4, 8, 9, 17, 19, ...).

LINKS

Table of n, a(n) for n=1..78.

FORMULA

A026794 * A051731 as infinite lower triangular matrices.

EXAMPLE

First few rows of the triangle: