A135387 Triangle read by rows, with (2, 1, 0, 0, 0, ...) in every column.

2, 1, 2, 0, 1, 2, 0, 0, 1, 2, 0, 0, 0, 1, 2, 0, 0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 0, 0, 1, 2

Offset

1,1

Comments

Let the triangle = M, then M^n * [1, 1, 0, 0, 0, ...] generates rows of triangle A118800. M^n * [1, 0, 0, 0, ...] generates rows of triangle A038207.

Eigensequence of the triangle = the Pell numbers, A000129: (1, 2, 5, 12, 29, ...). - Gary W. Adamson, Dec 29 2008

Links

Table of n, a(n) for n=1..45.

Formula

Triangle by columns (2, 1, 0, 0, 0, 0, 0, ...) in every column. By rows, (n-2) zeros followed by 1, 2.

Example

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

Crossrefs

Cf. A118800, A038207.

Cf. A000129. - Gary W. Adamson, Dec 29 2008

Sequence in context: A140083 A277729 A057985 * A321104 A127442 A357524

Adjacent sequences: A135384 A135385 A135386 * A135388 A135389 A135390

Keyword

nonn,tabl

Author

Gary W. Adamson, Dec 09 2007

Status

approved