OFFSET
1,1
COMMENTS
The asymptotic density of this sequence is (6/Pi^2) * Sum_{k>=1} f(a(k)) = 0.0237194..., where f(k) = A112526(k) * Product_{p|k} p/(p+1). - Amiram Eldar, Sep 24 2024
LINKS
FORMULA
A046660(a(n)) = 4. - Reinhard Zumkeller, Nov 29 2015
MATHEMATICA
Select[Range[2000], PrimeOmega[#]-PrimeNu[#]==4&]
PROG
(PARI) is(n)=bigomega(n)-omega(n)==4 \\ Charles R Greathouse IV, Sep 14 2015
(Haskell)
a195088 n = a195088_list !! (n-1)
a195088_list = filter ((== 4) . a046660) [1..]
-- Reinhard Zumkeller, Nov 29 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Harvey P. Dale, Sep 08 2011
STATUS
approved