A130277 Triangle read by rows: A130209 * A051731 as infinite lower triangular matrices.

1, 2, 2, 2, 0, 2, 3, 3, 0, 3, 2, 0, 0, 0, 2, 4, 4, 4, 0, 0, 4, 2, 0, 0, 0, 0, 0, 2, 4, 4, 0, 4, 0, 0, 0, 4, 3, 0, 3, 0, 0, 0, 0, 0, 3, 4, 4, 0, 0, 4, 0, 0, 0, 0, 4, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 6, 6, 6, 6, 0, 6, 0, 0, 0, 0, 0, 6, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 4, 4, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 4

Offset: 1

Author

Gary W. Adamson, May 18 2007

Keywords

• nonn
• tabl

Comments

Row sums = A035116: (1, 4, 4, 9, 4, 16, 4, 16, ...).

Right and left borders = A000005, d(n): (1, 2, 2, 3, 2, 4, 2, ...).

Examples

			First few rows of the triangle:
  1;
  2, 2;
  2, 0, 2;
  3, 3, 0, 3;
  2, 0, 0, 0, 2;
  4, 4, 4, 0, 0, 4;
  2, 0, 0, 0, 0, 0, 2;
  4, 4, 0, 4, 0, 0, 0, 4;
  ...
		

Crossrefs

Cf. A000005, A035116, A051731, A130209.

Extensions

a(56) corrected and more terms from Georg Fischer, Jun 05 2023