OFFSET
1,8
COMMENTS
Omega(n) is the number of prime divisors of n counted with multiplicity, A001222 (also called bigomega(n)).
Records are at 2^A053624(n). [Charles R Greathouse IV, Jul 29 2011]
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
EXAMPLE
a(8) = 2 because Omega(8) = 3 and the 2 odd divisors are {1, 3}.
MATHEMATICA
f[n_] := Block[{d = Divisors[PrimeOmega[n]]}, Count[OddQ[d], True]]; Table[f[n], {n, 80}]
PROG
(PARI) a(n)=if(n==1, 0, my(k=bigomega(n)); numdiv(k>>valuation(k, 2))) \\ Charles R Greathouse IV, Jul 29 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, Jul 29 2011
STATUS
approved