A097289 Contains exactly once every pair (i,j) satisfying 0 < i <= j.

1, 1, 2, 2, 1, 3, 3, 1, 4, 4, 2, 3, 1, 5, 5, 2, 4, 1, 6, 6, 2, 5, 3, 4, 1, 7, 7, 2, 6, 3, 5, 1, 8, 8, 2, 7, 3, 6, 4, 5, 1, 9, 9, 2, 8, 3, 7, 4, 6, 1, 10, 10, 2, 9, 3, 8, 4, 7, 5, 6, 1, 11, 11, 2, 10, 3, 9, 4, 8, 5, 7, 1, 12, 12, 2, 11, 3, 10, 4, 9, 5, 8, 6, 7, 1, 13, 13, 2, 12, 3, 11, 4, 10, 5, 9, 6, 8, 1

Offset

1,3

Comments

All pairs (i,j) having i>j occur (not necessarily uniquely) except those of the form (i,i-1) for i>=3. (Those are included at A097291.)

Links

Table of n, a(n) for n=1..98.

Formula

Obtained from A097283 by inserting m right after the first occurrence of m, for each positive integer m.

Crossrefs

Cf. A097290, A097291.

Sequence in context: A344087 A118816 A283904 * A294207 A288267 A237840

Adjacent sequences: A097286 A097287 A097288 * A097290 A097291 A097292

Keyword

nonn

Author

Clark Kimberling, Aug 05 2004

Status

approved