A075423 rad(n) - 1, where rad(n) is the squarefree kernel of n (A007947).

0, 1, 2, 1, 4, 5, 6, 1, 2, 9, 10, 5, 12, 13, 14, 1, 16, 5, 18, 9, 20, 21, 22, 5, 4, 25, 2, 13, 28, 29, 30, 1, 32, 33, 34, 5, 36, 37, 38, 9, 40, 41, 42, 21, 14, 45, 46, 5, 6, 9, 50, 25, 52, 5, 54, 13, 56, 57, 58, 29, 60, 61, 20, 1, 64, 65, 66, 33, 68, 69, 70, 5, 72, 73, 14, 37, 76, 77

Offset: 1

Author

Reinhard Zumkeller, Sep 15 2002

Keywords

• nonn

Comments

a(n) < n for all n, see A075425.

Crossrefs

A075424(n) = a(a(n)) for n>1.

Programs

PARI

a(n)=factorback(factor(n)[,1])-1 \\ Charles R Greathouse IV, Jul 09 2013