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

1,2

Comments

1 together with A033942.

Links

Table of n, a(n) for n=1..62.

Formula

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

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 *)

Prog

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

Crossrefs

Sequence in context: A160258 A071280 A033942 * A341610 A337373 A166083

Adjacent sequences: A111084 A111085 A111086 * A111088 A111089 A111090

Keyword

easy,nonn

Author

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

Extensions

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

Status

approved