A135151 A002260 + A128174 - I, I = Identity matrix.

1, 1, 2, 2, 2, 3, 1, 3, 3, 4, 2, 2, 4, 4, 5, 1, 3, 3, 5, 5, 6, 2, 2, 4, 4, 6, 6, 7, 1, 3, 3, 5, 5, 7, 7, 8, 2, 2, 4, 4, 6, 6, 8, 8, 9, 1, 3, 3, 5, 5, 7, 7, 9, 9, 10

Offset: 1

Author

Gary W. Adamson, Nov 21 2007

Keywords

• nonn
• tabl

Comments

A135152 is a companion triangle, both having row sums = A047838: (1, 3, 7, 11, 17, 23, 31, 39, ...).

Examples

			First few rows of the triangle:
  1;
  1, 2;
  2, 2, 3;
  1, 3, 3, 4;
  2, 2, 4, 4, 5;
  1, 3, 3, 5, 5, 6;
  2, 2, 4, 4, 6, 6, 7;
  ...
		

Crossrefs

Cf. A002260, A047838, A135152.

Formula

A002260 + A128174 - I, where I = Identity matrix, A002260 = (1; 1,2; 1,2,3; ...) and A128174 = (1; 0,1; 1,0,1; 0,1,0,1; ...).