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A264045
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Numbers n such that n and n+5 are consecutive semiprimes.
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3
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69, 77, 106, 161, 178, 221, 254, 309, 314, 329, 341, 386, 398, 417, 422, 473, 554, 662, 674, 689, 758, 794, 934, 974, 998, 1094, 1121, 1149, 1169, 1214, 1294, 1502, 1517, 1522, 1541, 1569, 1673
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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EXAMPLE
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MATHEMATICA
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Flatten[Position[Partition[Table[If[PrimeOmega[n]==2, 1, 0], {n, 2000}], 6, 1], _?(#=={1, 0, 0, 0, 0, 1}&)]] (* Harvey P. Dale, Dec 16 2015 *)
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PROG
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(PARI) is(n)=if(n%4==1, isprime((n+5)/2) && bigomega(n)==2, n%4==2 && isprime(n/2) && bigomega(n+5)==2) && bigomega(n+1)!=2 && bigomega(n+2)!=2 && bigomega(n+3)!=2 && bigomega(n+4)!=2 \\ Charles R Greathouse IV, Nov 02 2015
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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