A135858 A128229^2 * A000012.

1, 3, 1, 7, 5, 1, 13, 13, 7, 1, 21, 21, 21, 9, 1, 31, 31, 31, 31, 11, 1, 43, 43, 43, 43, 43, 13, 1, 57, 57, 57, 57, 57, 57, 15, 1, 73, 73, 73, 73, 73, 73, 73, 17, 1, 91, 91, 91, 91, 91, 91, 91, 91, 19, 1

Offset

1,2

Comments

Row sums = A135859: (1, 4, 13, 34, 73, 136, ...).

Links

Table of n, a(n) for n=1..55.

Formula

A128229^2 * A000012, where A128229 = a bidiagonal matrix with all 1's in the main diagonal and (1, 2, 3, ...) in the subdiagonal.

Example

First few rows of the triangle:
   1;
   3,  1;
   7,  5,  1;
  13, 13,  7,  1;
  21, 21, 21,  9,  1;
  31, 31, 31, 31, 11,  1;
  43, 43, 43, 43, 43, 13, 1;
  ...

Crossrefs

Cf. A128229, A135859.

Sequence in context: A271258 A100584 A185877 * A193845 A372938 A265706

Adjacent sequences: A135855 A135856 A135857 * A135859 A135860 A135861

Keyword

nonn,tabl

Author

Gary W. Adamson, Dec 01 2007

Status

approved