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

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:
   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;
  ...

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