OFFSET
1,2
COMMENTS
Let p be the largest prime factor of n; if p = prime(k) then set a(n) = k + 1. a(n) = A061395(n) + 1.
EXAMPLE
For n=30, the largest element of the set {1,2,3,5} (1 and prime divisors of 30) is 5, and 5 is a(n)=4th term of A008578, the extended set of primes.
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jaroslav Krizek, Apr 05 2009
EXTENSIONS
Edited by R. J. Mathar, Apr 06 2009
STATUS
approved