A131050 (1/5) * (A007318^4 - A007318^(-1)).

1, 3, 2, 13, 9, 3, 51, 52, 18, 4, 205, 255, 130, 30, 5, 819, 1230, 765, 260, 45, 6, 3277, 5733, 4305, 1785, 455, 63, 7, 13107, 26216, 22932, 11480, 3570, 728, 84, 8

Offset

1,2

Comments

Row sums = powers of 5: (1, 5, 25, 125, ...).

Left border = A015521: (1, 3, 13, 51, 205, 819, ...).

Links

Table of n, a(n) for n=1..36.

Formula

Let P = Pascal's triangle, A007318. Then A131050 = (1/5) * (P^4 - 1/P); deleting the right border of zeros.

Example

First few rows of the triangle:
    1;
    3,   2;
   13,   9,   3;
   51,  52,  18,  4;
  205, 255, 130, 30, 5;
  ...

Crossrefs

Cf. A015521, A131047, A131048, A131049, A131051.

Sequence in context: A245610 A191705 A252669 * A219374 A084416 A210604

Adjacent sequences: A131047 A131048 A131049 * A131051 A131052 A131053

Keyword

nonn,tabl

Author

Gary W. Adamson, Jun 12 2007

Status

approved