A131875 Triangle, A000012 * A131844 as infinite lower triangular matrices.

1, 5, 4, 12, 5, 7, 22, 6, 8, 10, 35, 7, 9, 11, 13, 51, 8, 10, 12, 14, 16, 70, 9, 11, 13, 15, 17, 19, 92, 10, 12, 14, 16, 18, 20, 22, 117, 11, 13, 15, 17, 19, 21, 23, 25, 145, 12, 14, 16, 18, 20, 22, 24, 26, 28

Offset: 0

Author

Gary W. Adamson, Jul 22 2007

Keywords

• nonn
• tabl

Comments

Left column = pentagonal numbers, A000326: (1, 5, 12, 22, ...).

Row sums = A001106: (1, 9, 24, 46, 75, 111, ...).

Examples

			First few rows of the triangle:
   1;
   5,  4;
  12,  5,  7;
  22,  6,  8, 10;
  35,  7,  9, 11, 13;
  51,  8, 10, 12, 14, 16;
  70,  9, 11, 13, 15, 17, 19;
  92, 10, 12, 14, 16, 18, 20, 22;
  ...
		

Crossrefs

Cf. A131844, A001106, A000326.