A131247 2*A052509 - A000012.

1, 1, 1, 1, 3, 1, 1, 5, 3, 1, 1, 7, 7, 3, 1, 1, 9, 13, 7, 3, 1, 1, 11, 21, 15, 7, 3, 1, 1, 13, 31, 29, 15, 7, 3, 1, 1, 15, 43, 51, 31, 15, 7, 3, 1, 1, 17, 57, 83, 61, 31, 15, 7, 3, 1

Offset

0,5

Comments

Row sums = A104161 starting (1, 2, 5, 10, 19, 34, 59, ...). Reversal, A131248 is generated from 2*A004070 - A000012.

Links

Table of n, a(n) for n=0..54.

Formula

2*A052509 - A000012, where A000012 = (1; 1,1; 1,1,1; ...).

Example

First few rows of the triangle:
  1;
  1,  1;
  1,  3,  1;
  1,  5,  3,  1;
  1,  7,  7,  3,  1;
  1,  9, 13,  7,  3,  1;
  1, 11, 21, 15,  7,  3,  1;
  ...

Crossrefs

Cf. A052509, A104161, A004070, A131248.

Sequence in context: A229288 A181109 A152720 * A114278 A134836 A180955

Adjacent sequences: A131244 A131245 A131246 * A131248 A131249 A131250

Keyword

nonn,tabl

Author

Gary W. Adamson, Jun 23 2007

Status

approved