OFFSET
3,1
COMMENTS
Csajbók and Kasza call this "lasttau(n)". Imre Kátai asks for its asymptotic behavior.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 3..10000
Tímea Csajbók and János Kasza, Iterating the tau-function, Annales Univ. Sci. Budapest., Sec. Math. 35 (2011), pp. 83-93.
PROG
(PARI) a(n)=while(!isprime(n), n=numdiv(n)); n \\ Charles R Greathouse IV, Nov 23 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
Charles R Greathouse IV, Nov 23 2011
STATUS
approved