A158948 Triangle read by rows, left border = natural numbers repeated (1, 1, 2, 2, 3, 3, ...); all other columns = (1, 0, 1, 0, 1, 0, ...).

1, 1, 1, 2, 0, 1, 2, 1, 0, 1, 3, 0, 1, 0, 1, 3, 1, 0, 1, 0, 1, 4, 0, 1, 0, 1, 0, 1, 4, 1, 0, 1, 0, 1, 0, 1, 5, 0, 1, 0, 1, 0, 1, 0, 1, 5, 1, 0, 1, 0, 1, 0, 1, 0, 1

Offset: 1

Author

Gary W. Adamson, Mar 31 2009

Keywords

• nonn
• tabf

Comments

Row sums = n. Eigensequence of the triangle = nonzero terms of A000071: (1, 2, 4, 7, 12, 20, ...) = ((F3 - 1), (F4 - 1), (F5 - 1), ...).

Examples

			First few rows of the triangle:
  1;
  1, 1;
  2, 0, 1;
  2, 1, 0, 1;
  3, 0, 1, 0, 1;
  3, 1, 0, 1, 0, 1;
  4, 0, 1, 0, 1, 0, 1;
  4, 1, 0, 1, 0, 1, 0, 1;
  5, 0, 1, 0, 1, 0, 1, 0, 1;
  5, 1, 0, 1, 0, 1, 0, 1, 0, 1;
  6, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1;
  6, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1;
  7, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1;
  ...
		

Crossrefs

Cf. A000071.

Formula

Triangle by rows, left border = natural numbers repeated (1, 1, 2, 2, 3, 3, ...); all other columns = (1, 0, 1, 0, 1, 0, ...).