A349188 Largest n-phobe number.
2, 24, 48, 240, 1440, 2400, 7440, 25920, 72000, 234000
Offset: 2
Examples
For n = 2, integers 1 and 2 are 2-phobe, then for m >= 3, every m = 1 + (m-1) with 1 < m-1 and 1 divides m-1, so, each m >= 3 is 2-phile number and a(2) = 2.
Links
- Diophante, A496 - Pentaphiles et pentaphobes (in French).
- Bernard Schott, Proof that a(6) = 1440 and other proofs.
Crossrefs
Extensions
a(6)-a(11) from David A. Corneth, Nov 19 2021
Comments