A064918 a(n) is the number of iterations of k -> A064916(k) to reach a prime, starting at n.

0, 0, 1, 0, 2, 0, 1, 1, 3, 0, 1, 0, 2, 1, 2, 0, 4, 0, 1, 2, 2, 0, 1, 2, 3, 1, 2, 0, 3, 0, 1, 1, 5, 1, 1, 0, 2, 2, 3, 0, 3, 0, 1, 1, 2, 0, 3, 1, 4, 1, 2, 0, 3, 2, 1, 3, 4, 0, 1, 0, 2, 1, 2, 1, 6, 0, 2, 3, 2, 0, 1, 0, 3, 2, 3, 1, 4, 0, 1, 1, 4, 0, 1, 3, 2, 1, 2, 0, 3, 1, 1, 2, 4, 1, 2, 0, 5, 2, 2, 0, 3, 0, 1, 1, 4

Offset: 2

Author

Reinhard Zumkeller, Oct 14 2001

Keywords

• nonn

Comments

a(p) = 0 for all primes p.

Examples

			a(6) = 2 as A064916(A064916(6)) = A064916(4) = 3 = A064917(6).
		

Links

• Harry J. Smith, Table of n, a(n) for n = 2..1000

Crossrefs

Cf. A064916, A064917, A064922.

Programs

PARI

lpf(n)= { local(f); f=factor(n); return(f[1, 1]) } { for (n=2, 1000, m=n; a=0; while (!isprime(m), L=lpf(m); m=m / L + L - 1; a++); write("b064918.txt", n, " ", a) ) } \\ Harry J. Smith, Sep 29 2009