OFFSET
1,8
COMMENTS
Places n where a(n) is prime are: 9, 10, 25, 27, 32, 36, 49, 64,...
Places n where a(n^2) is prime are: 3, 5, 6, 7, 8,...
Number of prime factors counted with multiplicity. - Harvey P. Dale, Jan 23 2019
EXAMPLE
a(8) = (number of prime factors)*8 - (sum of divisors) = 3*8 - (1+2+4+8) = 24 - 15 = 9.
MAPLE
A186170 := proc(n)
n*numtheory[bigomega](n)-numtheory[sigma](n) ;
end proc: # R. J. Mathar, Jun 15 2013
MATHEMATICA
Table[PrimeOmega[n]n-DivisorSigma[1, n], {n, 70}] (* Harvey P. Dale, Jan 23 2019 *)
PROG
(PARI) a(n)=n*bigomega(n)-sigma(n) \\ Charles R Greathouse IV, Mar 17 2014
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Irina Gerasimova, Jun 14 2013
STATUS
approved