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 A092126 Numbers n such that n, n+2, n+4, n+6 are semiprimes. 10
 213, 215, 299, 411, 1133, 1135, 1343, 1345, 1383, 1385, 1387, 1685, 1793, 1835, 1837, 1891, 1937, 1939, 1957, 2045, 2315, 2317, 2513, 2567, 2807, 2809, 2929, 3091, 3093, 3095, 3097, 3147, 3149, 3647, 3957, 3977, 3979, 4115, 4313, 4315, 4411, 4529, 4531 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Semiprimes in arithmetic progression. All terms are odd, see also A056809. LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 MATHEMATICA PrimeFactorExponentsAdded[n_] := Plus @@ Flatten[Table[ #[[2]], {1}] & /@ FactorInteger[n]]; Select[ Range[ 4626], PrimeFactorExponentsAdded[ # ] == PrimeFactorExponentsAdded[ # + 2] == PrimeFactorExponentsAdded[ # + 4] == PrimeFactorExponentsAdded[ # + 6] == 2 &] (* Robert G. Wilson v, Feb 24 2004 *) Transpose[SequencePosition[Table[If[PrimeOmega[n]==2, 1, 0], {n, 5000}], {1, _, 1, _, 1, _, 1}]][[1]] (* The program uses the SequencePosition function from Mathematica version 10 *) (* Harvey P. Dale, Feb 10 2016 *) CROSSREFS Cf. A056809, A070552, A092125, A092127, A092128, A092129. Sequence in context: A197106 A138568 A201104 * A252032 A252025 A238019 Adjacent sequences:  A092123 A092124 A092125 * A092127 A092128 A092129 KEYWORD easy,nonn AUTHOR Zak Seidov, Feb 22 2004 STATUS approved

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Last modified October 22 22:34 EDT 2019. Contains 328335 sequences. (Running on oeis4.)