A092129 Numbers n such that n, n+2, n+4, n+6, n+8, n+10, n+12 are semiprimes.

3091, 8129, 8131, 9983, 9985, 55559, 92603, 99443, 99445, 112709, 132077, 132079, 182749, 190937, 190939, 209479, 237449, 237451, 239089, 249689, 296779, 300449, 313411, 401429, 401431, 441677, 441679, 452639, 452641, 547157, 604487, 604489

Offset: 1

Author

Zak Seidov, Feb 22 2004

Keywords

• easy
• nonn

Comments

Semiprimes in arithmetic progression. All terms are odd, see also A056809.

Crossrefs

Cf. A056809, A070552, A092125, A092126, A092127, A092128.

Programs

Mathematica

PrimeFactorExponentsAdded[n_] := Plus @@ Flatten[Table[ #[[2]], {1}] & /@ FactorInteger[n]]; Select[ Range[ 631200], PrimeFactorExponentsAdded[ # ] == PrimeFactorExponentsAdded[ # + 2] == PrimeFactorExponentsAdded[ # + 4] == PrimeFactorExponentsAdded[ # + 6] == PrimeFactorExponentsAdded[ # + 8] == PrimeFactorExponentsAdded[ # + 10] == PrimeFactorExponentsAdded[ # + 12] == 2 &] (* Robert G. Wilson v, Feb 24 2004 *)
Select[Range[610000],Union[PrimeOmega[#+Range[0,12,2]]]=={2}&] (* Harvey P. Dale, Oct 14 2018 *)

Extensions

More terms from Don Reble, Feb 23 2004

More terms from Robert G. Wilson v, Feb 24 2004