A348330 Lexicographically earliest sequence of positive integers such that for any n > 0, the sum of the indices k < n such that a(k) = a(n) is strictly less than n.

1, 1, 2, 1, 2, 3, 3, 1, 2, 4, 4, 5, 5, 3, 6, 1, 6, 2, 7, 7, 8, 4, 8, 9, 9, 5, 10, 3, 10, 11, 11, 1, 6, 12, 12, 2, 13, 13, 14, 7, 14, 15, 15, 4, 8, 16, 16, 17, 17, 9, 18, 5, 18, 19, 19, 3, 10, 20, 20, 21, 21, 11, 22, 1, 22, 6, 23, 23, 24, 12, 24, 2, 25, 25, 26

Offset: 1

Author

Rémy Sigrist, Oct 13 2021

Keywords

• nonn

Comments

Every integer appears infinitely many times.

See table A348356 where the integers are arranged according to the present sequence.

Crossrefs

Cf. A000079, A348331, A348356, A348357.

Programs

PARI

s=vector(25); for (n=1, 75, for (k=1, oo, if (s[k]
				

Formula

a(n) = 1 iff n is a power of 2 (A000079).