A128140 - OEIS

A128140

A128132 * A004736.

1, 3, 2, 7, 5, 3, 13, 10, 7, 4, 21, 17, 13, 9, 5, 31, 26, 21, 16, 11, 6, 43, 37, 31, 25, 19, 13, 7, 57, 50, 43, 36, 29, 22, 15, 8, 73, 65, 57, 49, 41, 33, 25, 17, 9, 91, 82, 73, 64, 55, 46, 37, 28, 19, 10

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OFFSET

1,2

COMMENTS

Row sums = A006003, starting (1, 5, 15, 34, 65, 111, ...). Left border = A002061: (1, 3, 7, 13, 21, 31, 43, ...) A128139 = A004736 * A128132

LINKS

Table of n, a(n) for n=1..55.

FORMULA

A128132 * A004736 as infinite lower triangular matrices.

EXAMPLE

First few rows of the triangle:

3, 2;

7, 5, 3;

13, 10, 7, 4;

21, 17, 13, 9, 5;

31, 26, 21, 16, 11, 6;

43, 37, 31, 25, 19, 13, 7;

...

CROSSREFS

Cf. A128132, A004736, A006003, A004006, A128139.

Sequence in context: A075627 A281825 A011384 * A213579 A137225 A213777

Adjacent sequences: A128137 A128138 A128139 * A128141 A128142 A128143

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Feb 16 2007

STATUS

approved