A092127 Numbers n such that n, n+2, n+4, n+6, n+8 are semiprimes.

213, 1133, 1343, 1383, 1385, 1835, 1937, 2315, 2807, 3091, 3093, 3095, 3147, 3977, 4313, 4529, 4835, 5089, 5609, 5611, 6185, 6533, 7141, 8129, 8131, 8133, 8135, 9753, 9755, 9983, 9985, 9987, 9989, 10401, 10403, 11013, 11015, 11099, 11663, 12053

Offset

1,1

Comments

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

Links

Table of n, a(n) for n=1..40.

Mathematica

PrimeFactorExponentsAdded[n_] := Plus @@ Flatten[Table[ #[[2]], {1}] & /@ FactorInteger[n]]; Select[ Range[ 12054], PrimeFactorExponentsAdded[ # ] == PrimeFactorExponentsAdded[ # + 2] == PrimeFactorExponentsAdded[ # + 4] == PrimeFactorExponentsAdded[ # + 6] == PrimeFactorExponentsAdded[ # + 8] == 2 &] (* Robert G. Wilson v, Feb 24 2004 *)

Crossrefs

Cf. A056809, A070552, A092125, A092126, A092128, A092129.

Sequence in context: A085309 A252024 A302256 * A082967 A212312 A201342

Adjacent sequences: A092124 A092125 A092126 * A092128 A092129 A092130

Keyword

easy,nonn

Author

Zak Seidov, Feb 22 2004

Status

approved