A279690 Smallest number with equivalent prime tower factorization as n.

1, 2, 2, 4, 2, 6, 2, 8, 8, 6, 2, 12, 2, 6, 6, 16, 2, 18, 2, 12, 6, 6, 2, 18, 8, 6, 4, 12, 2, 30, 2, 8, 6, 6, 6, 36, 2, 6, 6, 40, 2, 30, 2, 12, 40, 6, 2, 48, 8, 18, 6, 12, 2, 12, 6, 40, 6, 6, 2, 60, 2, 6, 40, 64, 6, 30, 2, 12, 6, 30, 2, 72, 2, 6, 40, 12, 6, 30

Offset: 1

Author

Rémy Sigrist, Dec 17 2016

Keywords

• nonn

Comments

A279686 defines the prime tower factorization equivalence classes.

This sequence is to A279686 what A046523 is to A025487.

a(a(n))=a(n) for any n>0.

a(n)=n iff n belongs to A279686.

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10000
• Rémy Sigrist, Prime tower factorization of the first terms
• Rémy Sigrist, PARI program for A279690

Crossrefs

Cf. A279686, A025487, A046523.