A065225 Fill a triangular array by rows by writing numbers 1 up to b(0), 1 up to b(1), etc., where b(n) are the 9-gonal (nonagonal) numbers. The final elements of the rows form a(n).

1, 2, 5, 9, 5, 11, 18, 2, 11, 21, 32, 44, 11, 25, 40, 56, 73, 16, 35, 55, 76, 98, 10, 34, 59, 85, 112, 140, 15, 45, 76, 108, 141, 175, 6, 42, 79, 117, 156, 196, 237, 18, 61, 105, 150, 196, 243, 291, 15, 65, 116, 168, 221, 275, 330, 386, 47, 105, 164, 224, 285, 347, 410

Offset

0,2

Links

Table of n, a(n) for n=0..62.

Crossrefs

Cf. A001106, A064766, A064865, A065221-A065224, A065226-A065234.

Sequence in context: A118907 A246206 A200336 * A175640 A204913 A198455

Adjacent sequences: A065222 A065223 A065224 * A065226 A065227 A065228

Keyword

easy,nonn

Author

Floor van Lamoen, Oct 22 2001

Status

approved