A111087 Neither primes nor semiprimes.

1, 8, 12, 16, 18, 20, 24, 27, 28, 30, 32, 36, 40, 42, 44, 45, 48, 50, 52, 54, 56, 60, 63, 64, 66, 68, 70, 72, 75, 76, 78, 80, 81, 84, 88, 90, 92, 96, 98, 99, 100, 102, 104, 105, 108, 110, 112, 114, 116, 117, 120, 124, 125, 126, 128, 130, 132, 135, 136, 138, 140, 144

Offset: 1

Author

Noelle Clou (keynews.tv(AT)skynet.be), Oct 12 2005

Keywords

• easy
• nonn

Comments

1 together with A033942.

Programs

Mathematica

f[n_] := Plus @@ Last /@ FactorInteger[n]; Select[ Range[146], f[ # ] != 1 && f[ # ] != 2 &] (* Robert G. Wilson v *)
Join[{1},Select[Range[200],PrimeOmega[#]>2&]] (* Harvey P. Dale, Mar 12 2018 *)

PARI

is(n)=bigomega(n)>2 || n==1 \\ Charles R Greathouse IV, Nov 13 2016

Formula

a(n) = n + O(n log log n/log n). - Charles R Greathouse IV, Nov 13 2016

Extensions

More terms from Robert G. Wilson v, Oct 12 2005