A316665 a(n) is the least k > 0 such that k*n does not belong to A002202.

3, 7, 1, 17, 1, 15, 1, 19, 1, 5, 1, 43, 1, 1, 1, 19, 1, 5, 1, 17, 1, 7, 1, 167, 1, 1, 1, 11, 1, 3, 1, 19, 1, 1, 1, 67, 1, 1, 1, 17, 1, 17, 1, 7, 1, 5, 1, 211, 1, 1, 1, 7, 1, 11, 1, 13, 1, 3, 1, 139, 1, 1, 1, 31, 1, 9, 1, 1, 1, 5, 1, 109, 1, 1, 1, 1, 1, 3, 1

Offset: 1

Author

Rémy Sigrist, Jul 10 2018

Keywords

• nonn

Comments

All terms are odd.

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10000
• Rémy Sigrist, Scatterplot of (x, y) such that 1 <= x, y <= 500 and x*y does not belong to A002202

Crossrefs

Cf. A002202, A007617.

Programs

PARI

a(n) = forstep (k=1, oo, 2, if (!istotient(n*k), return (k)))

Formula

a(n) = 1 iff n belongs to A007617.