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A176140 Semiprimes s such that both s + 3 and s - 3 are primes. 0
10, 14, 26, 34, 86, 106, 134, 194, 226, 254, 274, 314, 334, 386, 446, 566, 974, 1094, 1126, 1226, 1234, 1286, 1294, 1486, 1546, 1874, 2066, 2374, 2386, 2554, 2854, 2906, 2966, 3086, 3166, 3254, 3326, 3466, 3694, 4054, 4286, 4594, 4786, 4874, 4934, 4954 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

2*5=10-+3->7,13 primes,...

LINKS

Table of n, a(n) for n=1..46.

MATHEMATICA

f[n_]:=Last/@FactorInteger[n]=={1, 1}; lst={}; Do[If[f[n]&&PrimeQ[n-3]&&PrimeQ[n+3], AppendTo[lst, n]], {n, 0, 4*7!}]; lst

CROSSREFS

Cf. A125215, A125216

Sequence in context: A175664 A053690 A177948 * A031028 A176810 A115603

Adjacent sequences:  A176137 A176138 A176139 * A176141 A176142 A176143

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Apr 09 2010

EXTENSIONS

Definition corrected by Zak Seidov, May 06 2013

STATUS

approved

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Last modified May 28 20:12 EDT 2017. Contains 287241 sequences.