A107065 Riordan array (1/(1-x),x(1+x+x^2+x^3)).

1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 4, 6, 4, 1, 1, 4, 10, 10, 5, 1, 1, 4, 13, 20, 15, 6, 1, 1, 4, 15, 32, 35, 21, 7, 1, 1, 4, 16, 44, 66, 56, 28, 8, 1, 1, 4, 16, 54, 106, 121, 84, 36, 9, 1, 1, 4, 16, 60, 150, 222, 204, 120, 45, 10, 1, 1, 4, 16, 63, 190, 357, 420, 323, 165, 55, 11, 1, 1, 4, 16

Offset

0,5

Comments

Row sums are A107066. Diagonal sums are A023436(n+1).

Links

Table of n, a(n) for n=0..80.

Example

Triangle begins
  1;
  1, 1;
  1, 2, 1;
  1, 3, 3, 1;
  1, 4, 6, 4, 1;
  1, 4, 10, 10, 5, 1;
  1, 4, 13, 20, 15, 6, 1;
  ...

Crossrefs

Cf. A107066, A023436.

Sequence in context: A216219 A180181 A128629 * A008975 A140280 A140586

Adjacent sequences: A107062 A107063 A107064 * A107066 A107067 A107068

Keyword

easy,nonn,tabl

Author

Paul Barry, May 10 2005

Status

approved