A128116 A128064 * A122432 (unsigned).

1, 5, 2, 12, 7, 3, 22, 15, 9, 4, 35, 26, 18, 11, 5, 51, 40, 30, 21, 13, 6, 70, 57, 45, 34, 24, 15, 7, 92, 77, 63, 50, 38, 27, 17, 8, 117, 100, 84, 69, 55, 42, 30, 19, 9, 145, 126, 108, 91, 75, 60, 46, 33, 21, 10

Offset: 1

Author

Gary W. Adamson, Feb 14 2007

Keywords

• nonn
• tabl

Comments

Left border of the triangle = A000326, the pentagonal numbers: (1, 5, 12, 22, 35, ...).

Row sums = A002412: (1, 7, 22, 50, 95, ...).

Examples

			First few rows of the triangle:
   1;
   5,  2;
  12,  7,  3;
  22, 15,  9,  4;
  35, 26, 18, 11,  5;
  51, 40, 30, 21, 13,  6;
  70, 57, 45, 34, 24, 15,  7;
  ...
		

Crossrefs

Cf. A128064, A122432, A000326, A002412.

Formula

A128064 * A122432 (unsigned), where the unsigned version of A122432 = (1; 3, 1; 6, 3, 1; 10, 6, 3, 1; ...).