A199970 a(n) = the smallest number m with the smallest non-divisor n such that 1<n<m, or 0 if no such m exists.

0, 3, 4, 6, 12, 0, 60, 420, 840, 0, 2520, 0, 27720, 0, 0, 360360, 720720, 0, 12252240, 0, 0, 0, 232792560, 0, 5354228880

Offset

1,2

Links

Table of n, a(n) for n=1..25.

Formula

a(n) > 0 for prime powers n = p^k (p prime, k >= 0) else 0.

Example

 a(7) = 60 because 60 is the smallest number such that numbers k < 7 divides 60 but number 7 is not divisor of 60.

Crossrefs

Cf. A199968, A199969.

Sequence in context: A192813 A048229 A002090 * A283738 A366535 A368469

Adjacent sequences: A199967 A199968 A199969 * A199971 A199972 A199973

Keyword

nonn

Author

Jaroslav Krizek, Nov 26 2011

Status

approved