A128137 A002260 * A128132.

1, -1, 4, -1, 1, 9, -1, 1, 5, 16, -1, 1, 5, 11, 25, -1, 1, 5, 11, 19, 36, -1, 1, 5, 11, 19, 29, 49, -1, 1, 5, 11, 19, 29, 41, 64, -1, 1, 5, 11, 19, 29, 41, 55, 81, -1, 1, 5, 11, 19, 29, 41, 55, 71, 100

Offset: 1

Author

Gary W. Adamson, Feb 16 2007

Keywords

• tabl
• sign

Comments

Deleting the right and left borders gives terms of A028387: (1, 5, 11, 29, 29, 41, 55, 71, ...). Row sums = A064999: (1, 3, 9, 21, 41, ...).

Examples

			First few rows of the triangle:
   1;
  -1, 4;
  -1, 1, 9;
  -1, 1, 5, 16;
  -1, 1, 5, 11, 25;
  -1, 1, 5, 11, 19, 36;
  -1, 1, 5, 11, 19, 29, 49;
  ...
		

Crossrefs

Cf. A002260, A128132, A028387, A128136, A064999.

Formula

A002260 * A128132 as infinite lower triangular matrices.