A134235 Triangle read by rows: a(1) = 1; then n-th row = n terms of (n+2), (n+4), (n+6), ..., n.

1, 4, 2, 5, 7, 3, 6, 8, 10, 4, 7, 9, 11, 13, 5, 8, 10, 12, 14, 16, 6, 9, 11, 13, 15, 17, 19, 7, 10, 12, 14, 16, 18, 20, 22, 8, 11, 13, 15, 17, 19, 21, 23, 25, 9, 12, 14, 16, 18, 20, 22, 24, 26, 28, 10

Offset

1,2

Comments

Row sums = the hexagonal numbers, A000384: (1, 6, 15, 28, 45, 66, 91, ...).

Links

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

Example

First few rows of the triangle:
  1;
  4,  2;
  5,  7,  3;
  6,  8, 10,  4;
  7,  9, 11, 13,  5;
  8, 10, 12, 14, 16,  6;
  9, 11, 13, 15, 17, 19,  7;
  ...

Crossrefs

Cf. A000384.

Sequence in context: A260623 A199625 A020849 * A266626 A159979 A198233

Adjacent sequences: A134232 A134233 A134234 * A134236 A134237 A134238

Keyword

nonn,tabl

Author

Gary W. Adamson, Oct 14 2007

Status

approved