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

1,1

Comments

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

Links

Table of n, a(n) for n=1..32.

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 *)

Crossrefs

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

Sequence in context: A268578 A268862 A277786 * A251871 A206132 A187305

Adjacent sequences: A092126 A092127 A092128 * A092130 A092131 A092132

Keyword

easy,nonn

Author

Zak Seidov, Feb 22 2004

Extensions

More terms from Don Reble, Feb 23 2004

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

Status

approved