A128141 A122432 (unsigned) * A128132.

1, 2, 2, 3, 5, 3, 4, 9, 8, 4, 5, 14, 15, 11, 5, 6, 20, 24, 21, 14, 6, 7, 27, 35, 34, 27, 17, 7, 8, 35, 48, 50, 44, 33, 20, 8, 9, 44, 63, 69, 65, 54, 39, 23, 9, 10, 54, 80, 91, 90, 80, 64, 45, 26, 10

Offset

1,2

Comments

Row sums = A006522 starting (1, 4, 11, 25, 50, 91, ...). A128142 = A128132 * A122432.

Links

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

Formula

Unsigned A122432 * A128132 as infinite lower triangular matrices; where unsigned A122432 = (1; 3, 1; 6, 3, 1; ...).

Example

First few rows of the triangle:
  1;
  2,  2;
  3,  5,  3;
  4,  9,  8,  4;
  5, 14, 15, 11,  5;
  6, 20, 24, 21, 14,  6;
  7, 27, 35, 34, 27, 17,  7;
  ...

Crossrefs

Cf. A122432, A128132, A006522, A128142, A006325.

Sequence in context: A061177 A129312 A115262 * A252829 A014430 A360196

Adjacent sequences: A128138 A128139 A128140 * A128142 A128143 A128144

Keyword

nonn,tabl

Author

Gary W. Adamson, Feb 16 2007

Status

approved