A134447 A002260 * A128174.

1, 1, 2, 4, 2, 3, 4, 6, 3, 4, 9, 6, 8, 4, 5, 9, 12, 8, 10, 5, 6, 16, 12, 15, 10, 12, 6, 7, 16, 20, 15, 18, 12, 14, 7, 8, 25, 20, 24, 18, 21, 14, 16, 8, 9, 25, 30, 24, 28, 21, 24, 16, 18, 9, 10

Offset

1,3

Comments

Row sums = A049778: (1, 3, 9, 17, 32, 50, 78, ...).

Links

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

Formula

A002260 * A128174 as infinite lower triangular matrices.

Example

First few rows of the triangle:
   1;
   1,  2;
   4,  2,  3;
   4,  6,  3,  4;
   9,  6,  8,  4,  5;
   9, 12,  8, 10,  5,  6;
  16, 12, 15, 10, 12,  6,  7;
  ...

Crossrefs

Cf. A128174, A002260, A049778.

Sequence in context: A331810 A182817 A082864 * A093056 A271320 A354739

Adjacent sequences: A134444 A134445 A134446 * A134448 A134449 A134450

Keyword

nonn,tabl

Author

Gary W. Adamson, Oct 25 2007

Status

approved