OFFSET
1,1
COMMENTS
This is to A164865 [Sum of the distinct semiprime divisors of the n-th number with two or more distinct semiprime divisors], as bigomega [A001222, Number of prime divisors of n (counted with multiplicity)] is to omega [A001221, Number of distinct primes dividing n].
The sum of semiprime divisors (with multiplicity) of all k such that A086971(k) > 1.
EXAMPLE
a(1) = 16 because the first number (greater than 1) such that the sum of numbers of prime factors with and without repetitions does not equal the number of divisors, is a(2) = 12 = (2^2)*3 whose semiprime factors are (2^2 = 4) once and (2*3) with multiplicity two hence (4*1)*1 + (3*3)*2 = 4 + 12 = 16.
a(6) = 31 because 30 = 2*3*5 has multiplicity one semiprime factors (2*3), (2*5), (3*5), which sum to 6+10+15 = 31.
CROSSREFS
KEYWORD
nonn
AUTHOR
Jonathan Vos Post, Sep 02 2010
EXTENSIONS
Formula, edits, and more terms from Charles R Greathouse IV, Sep 03 2010
STATUS
approved