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A092126 Numbers n such that n, n+2, n+4, n+6 are semiprimes. +0
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; listen)
OFFSET

1,1

COMMENT

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

MATHEMATICA

PrimeFactorExponentsAdded[n_] := Plus @@ Flatten[Table[ #[[2]], {1}] & /@ FactorInteger[n]]; Select[ Range[ 4626], PrimeFactorExponentsAdded[ # ] == PrimeFactorExponentsAdded[ # + 2] == PrimeFactorExponentsAdded[ # + 4] == PrimeFactorExponentsAdded[ # + 6] == 2 &] (from Robert G. Wilson v Feb 24 2004)

CROSSREFS

Cf. A056809, A070552, A092125, A092127, A092128, A092129.

Sequence in context: A007942 A079794 A138568 this_sequence A085309 A092127 A082967

Adjacent sequences: A092123 A092124 A092125 this_sequence A092127 A092128 A092129

KEYWORD

easy,nonn

AUTHOR

Zak Seidov (zakseidov(AT)yahoo.com), Feb 22 2004

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Last modified December 18 21:37 EST 2009. Contains 171024 sequences.


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