A130269 A002260 * A051340.

1, 3, 4, 6, 7, 9, 10, 11, 13, 16, 15, 16, 18, 21, 25, 21, 22, 24, 27, 31, 36, 28, 29, 31, 34, 38, 43, 49, 36, 37, 39, 42, 46, 51, 57, 64, 45, 46, 48, 51, 55, 60, 66, 73, 81, 55, 56, 58, 61, 65, 70, 76, 83, 91, 100

Offset

1,2

Comments

Row sums = A002412: (1, 7, 22, 50, 95, ...).

Links

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

Formula

A002260 * A051340 as infinite lower triangular matrices.

Example

First few rows of the triangle:
   1;
   3,  4;
   6,  7,  9;
  10, 11, 13, 16;
  15, 16, 18, 21, 25,
  21, 22, 24, 27, 31, 36;
  28, 29, 31, 34, 38, 43, 49;
  ...

Crossrefs

Cf. A002260, A051340, A002412.

Sequence in context: A184429 A248185 A357504 * A290730 A369856 A246443

Adjacent sequences: A130266 A130267 A130268 * A130270 A130271 A130272

Keyword

nonn,tabl

Author

Gary W. Adamson, May 18 2007

Status

approved