A133804 Triangle read by rows: A007318 * A133080 * A133566.

1, 2, 1, 3, 3, 1, 4, 7, 4, 1, 5, 14, 10, 5, 1, 6, 25, 20, 16, 6, 1, 7, 41, 35, 41, 21, 7, 1, 8, 63, 56, 91, 56, 29, 8, 1, 9, 92, 84, 182, 126, 92, 36, 9, 1, 10, 129, 120, 336, 252, 246, 120, 46, 10, 1, 11, 175, 165, 582, 462, 582, 330, 175, 55, 11, 1, 12, 231, 220, 957, 792, 1254, 792, 550, 220, 67, 12, 1

Offset

1,2

Comments

Row sums = A133124: (1, 3, 7, 16, 35, 74, 153, ...).

A133805 = binomial transform of (A133566 * A133080).

Links

Table of n, a(n) for n=1..78.

Formula

Binomial transform of (A133080 * A133566), where A133080 * A133566 = an infinite lower triangular matrix with (1,1,1,...) in the main and subdiagonals and (0,1,0,1,0,...) in the subsubdiagonal.

Example

First few rows of the triangle:
  1;
  2,  1;
  3,  3,  1;
  4,  7,  4,  1;
  5, 14, 10,  5,  1;
  6, 25, 20, 16,  6,  1;
  7, 41, 35, 41, 21,  7,  1;
  ...

Crossrefs

Cf. A133080, A133124, A133566.

Sequence in context: A126277 A253273 A055129 * A185943 A352001 A208337

Adjacent sequences: A133801 A133802 A133803 * A133805 A133806 A133807

Keyword

nonn,tabl

Author

Gary W. Adamson, Sep 23 2007

Extensions

a(21) = 1 inserted and more terms from Georg Fischer, Jun 08 2023

Status

approved