A146297 Integers which are not the sum of a 6-almost prime and a prime.

2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 68, 70, 72, 73, 74, 76, 78, 79

Offset

2,1

Comments

Largest known term is 446185740 (see b-file). No more terms < 10^9.

Links

Donovan Johnson, Table of n, a(n) for n=2..20150

Example

68 is in this sequence because no 6-almost prime and a prime sum to 68. 69 is not in this sequence because the sum of 64 (6-almost prime) and 5 (prime) is 69.

Mathematica

Complement[Range[1000], Union@Flatten@Outer[Plus, Select[Range[1000], PrimeOmega[#] == 6 &], Prime[Range[PrimePi[1000]]]]] (* Robert Price, Jun 16 2019 *)

Crossrefs

Cf. A000040, A046306, A130588, A146295, A146296.

Sequence in context: A153671 A090107 A130696 * A296876 A144972 A166719

Adjacent sequences: A146294 A146295 A146296 * A146298 A146299 A146300

Keyword

nonn

Author

Donovan Johnson, Nov 05 2008

Status

approved