A146295 Integers which are not the sum of a 4-almost prime and a prime.

2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 20, 22, 24, 25, 28, 30, 32, 34, 36, 40, 44, 46, 48, 50, 52, 54, 60, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 96, 108, 114, 116, 120, 126, 130, 132, 136, 144, 150, 156, 162, 168, 174, 180, 204, 210, 216, 240, 246, 258

Offset

2,1

Comments

Largest term is 60060 (see b-file). No more terms < 10^8. Conjectured to be complete.

Links

Donovan Johnson, Table of n, a(n) for n=2..196

Example

20 is in this sequence because no 4-almost prime and a prime sum to 20. 21 is not in this sequence because the sum of 16 (4-almost prime) and 5 (prime) is 21.

Mathematica

Complement[Range[1000], Union@Flatten@Outer[Plus, Select[Range[1000], PrimeOmega[#] == 4 &], Prime[Range[PrimePi[1000]]]]] (* Robert Price, Jun 16 2019 *)

Crossrefs

Cf. A000040, A014613, A130588, A146296, A146297.

Sequence in context: A322463 A275156 A188459 * A123719 A113221 A113219

Adjacent sequences: A146292 A146293 A146294 * A146296 A146297 A146298

Keyword

fini,nonn

Author

Donovan Johnson, Nov 05 2008

Status

approved