OFFSET
1,1
EXAMPLE
a(6) = 2 because C(6) = 12 = 3*2^2 and the largest prime factor of power 2^2 is 2.
a(28) = 0 because C(28) = 42 = 2*3*7 is the product of distinct primes
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Giovanni Teofilatto, Nov 17 2005
EXTENSIONS
a(28) changed by Michael B. Porter, Feb 02 2010
STATUS
approved