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

1,2

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, ...).

Links

Table of n, a(n) for n=1..105.

Example

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.

Sequence in context: A118205 A216265 A336694 * A109135 A264136 A274850

Adjacent sequences: A130274 A130275 A130276 * A130278 A130279 A130280

Keyword

nonn,tabl

Author

Gary W. Adamson, May 18 2007

Extensions

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

Status

approved