A131049 (1/4) * (A007318^3 - A007318^(-1)).

1, 2, 2, 7, 6, 3, 20, 28, 12, 4, 61, 100, 70, 20, 5, 182, 366, 300, 140, 30, 6, 547, 1274, 1281, 700, 245, 42, 7, 1640, 4376, 5096, 3416, 1400, 392, 56, 8, 4921, 14760, 19692, 15288, 7686, 2520, 588, 72, 9

Offset

1,2

Comments

Row sums = powers of 4: (1, 4, 16, 64, ...).

Left border = A015518: (1, 2, 7, 20, 61, 182, ...).

Links

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

Formula

(1/4) * (P^3 - 1/P), where P = Pascal's triangle, A007318. Delete right border of zeros.

Example

First few rows of the triangle:
    1;
    2,    2;
    7,    6,    3;
   20,   28,   12,   4;
   61,  100,   70,  20,   5;
  182,  366,  300, 140,  30,  6;
  547, 1274, 1281, 700, 245, 42, 7;
  ...

Crossrefs

Cf. A015518, A007318, A131047, A131048, A131050, A131051.

Sequence in context: A300126 A006748 A193548 * A142070 A152825 A347073

Adjacent sequences: A131046 A131047 A131048 * A131050 A131051 A131052

Keyword

nonn,tabl

Author

Gary W. Adamson, Jun 12 2007

Status

approved