A128077 A128064 * A002260.

1, 1, 4, 1, 2, 9, 1, 2, 3, 16, 1, 2, 3, 4, 25, 1, 2, 3, 4, 5, 36, 1, 2, 3, 4, 5, 6, 49, 1, 2, 3, 4, 5, 6, 7, 64

Offset

1,3

Comments

Row sums = the pentagonal numbers, A000326: 1, 5, 12, 22, 35, 51, ...

Links

Table of n, a(n) for n=1..36.

Formula

A128064 * A002260 as infinite lower triangular matrices. Triangle read by rows, a(1) = 1; n-th row = first (n-1) terms of (1, 2, 3, ...) followed by n^2.

Example

First few rows of the triangle:
  1;
  1, 4;
  1, 2, 9;
  1, 2, 3, 16;
  1, 2, 3,  4, 25;
  ...

Crossrefs

Cf. A128064, A002260, A000326, A128078.

Sequence in context: A133883 A279816 A004160 * A128078 A331152 A264922

Adjacent sequences: A128074 A128075 A128076 * A128078 A128079 A128080

Keyword

nonn,tabl

Author

Gary W. Adamson, Feb 14 2007

Status

approved