OFFSET
2,2
FORMULA
If p_1*p_2*p_3* ... *p_m=n is the unique prime factorization of n, then a(n)=sum{1<=k<=m, ds_2(p_k)}, where ds_2 is the digital sum base 2.
EXAMPLE
a(6)=3, since 6=2*3 and so a(6)=ds_2(2)+ds_2(3)=1+2.
CROSSREFS
KEYWORD
dead
AUTHOR
Hieronymus Fischer, Nov 11 2007
STATUS
approved