A131843 Triangle read by rows: 2*A131821 - A000012.

1, 3, 3, 5, 1, 5, 7, 1, 1, 7, 9, 1, 1, 1, 9, 11, 1, 1, 1, 1, 11, 13, 1, 1, 1, 1, 1, 13, 15, 1, 1, 1, 1, 1, 1, 15, 17, 1, 1, 1, 1, 1, 1, 1, 17, 19, 1, 1, 1, 1, 1, 1, 1, 1, 19, 21, 1, 1, 1, 1, 1, 1, 1, 1, 1, 21, 23, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 23, 25, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 25, 27, 1, 1, 1, 1, 1

Offset

0,2

Comments

Row sums = 5*n + 1, A016861: (1, 6, 11, 16, 21, ...).

Links

B. D. Swan, Table of n, a(n) for n = 0..100000

Formula

2*A131821 - A000012 as an infinite lower triangular matrix. 2*n - 1, (1, 3, 5, 7, ...) as right and left borders, with the rest zeros.

Example

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

Crossrefs

Cf. A016861, A131821.

Sequence in context: A205853 A240594 A079887 * A205550 A209389 A337544

Adjacent sequences: A131840 A131841 A131842 * A131844 A131845 A131846

Keyword

nonn,tabl,easy

Author

Gary W. Adamson, Jul 21 2007

Extensions

Corrected and edited by B. D. Swan (bdswan(AT)gmail.com), Dec 20 2008

Status

approved