OFFSET
1,1
COMMENTS
Semiprimes in arithmetic progression. All terms are odd, see also A056809.
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
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