A097288 Rectangular array read by antidiagonals obtained from A097287 by deleting the zeros.

2, 1, 6, 3, 4, 12, 7, 5, 8, 20, 13, 9, 10, 14, 30, 21, 15, 11, 16, 22, 42, 31, 23, 17, 18, 24, 32, 56, 43, 33, 25, 19, 26, 34, 44, 72, 57, 45, 35, 27, 28, 36, 46, 58, 90, 73, 59, 47, 37, 29, 38, 48, 60, 74, 110, 91, 75, 61, 49, 39, 40, 50, 62, 76, 92, 132, 111, 93, 77, 63, 51

Offset

1,1

Comments

As a sequence, this is a permutation of the natural numbers. Evens lie on or below the main diagonal; odds, above. The triangle formed by the evens is twice that of A066182.

Links

Table of n, a(n) for n=1..71.

Example

Northwest corner:
2 1 3 7 13
6 4 5 9 15
12 8 10 11 17
20 14 16 18 19

Crossrefs

Cf. A097287.

Sequence in context: A077172 A160047 A249990 * A223894 A308573 A171178

Adjacent sequences: A097285 A097286 A097287 * A097289 A097290 A097291

Keyword

nonn,tabl

Author

Clark Kimberling, Aug 05 2004

Status

approved