OFFSET
1,16
COMMENTS
Number of factorizations of n into factors k > 1 for which there is an even number of primes (when counted with multiplicity, A001222) in their prime factorization.
LINKS
FORMULA
EXAMPLE
Of the eleven divisors of 96 larger than one, the following: [4, 6, 16, 24, 96] are terms of A028260 because they have an even number of prime factors when counted with repetition. Using them, we can factor 96 in four possible ways, as 96 = 24*4 = 16*6 = 6*4*4, therefore a(96) = 4.
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Apr 17 2022
STATUS
approved