A359652 Lexicographically earliest sequence of positive integers such that no three terms a(j), a(j+k), a(j+2k) (for any j and k) form an arithmetic or geometric progression.

1, 1, 2, 1, 1, 2, 2, 5, 5, 1, 1, 2, 1, 1, 2, 2, 5, 5, 2, 5, 5, 6, 6, 10, 6, 6, 11, 1, 1, 2, 1, 1, 2, 2, 5, 5, 1, 1, 2, 1, 1, 2, 2, 5, 5, 2, 5, 5, 6, 6, 10, 6, 6, 11, 11, 5, 5, 6, 6, 12, 6, 6, 12, 2, 12, 14, 13, 13, 3, 13, 12, 12, 15, 13, 12, 12, 13, 15, 13, 17

Offset: 1

Author

Neal Gersh Tolunsky, Jan 09 2023

Keywords

• nonn
• look

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A229037, A268811.

Formula

a(n) <= (n^2+1)/2.

Extensions

More terms from Alois P. Heinz, Jan 09 2023