A097291 Contains exactly once every pair (i,j) of positive integers.

1, 1, 2, 2, 1, 3, 3, 2, 3, 1, 4, 4, 2, 4, 3, 4, 1, 5, 5, 2, 5, 3, 5, 4, 5, 1, 6, 6, 2, 6, 3, 6, 4, 6, 5, 6, 1, 7, 7, 2, 7, 3, 7, 4, 7, 5, 7, 6, 7, 1, 8, 8, 2, 8, 3, 8, 4, 8, 5, 8, 6, 8, 7, 8, 1, 9, 9, 2, 9, 3, 9, 4, 9, 5, 9, 6, 9, 7, 9, 8, 9, 1, 10, 10, 2, 10, 3, 10, 4, 10, 5, 10, 6, 10, 7, 10, 8, 10, 9, 10

Offset: 1

Author

Clark Kimberling, Aug 05 2004

Keywords

• nonn

Comments

The pairs (i,j) are ordered in segments thus: segment 1: 1 segment 2: 1 2 2 segment 3: 1 3 3 2 3 segment 4: 1 4 4 2 4 3 4 segment 5: 1 5 5 2 5 3 5 4 5 and so on.

Crossrefs

Cf. A098289.