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A165683
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Primes of form 3*p*(p-1)+1 with p also a prime.
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3
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7, 19, 61, 127, 331, 2437, 2791, 5419, 8269, 10267, 13267, 23497, 35317, 55897, 73477, 89269, 115837, 170647, 292969, 360187, 372769, 452797, 603457, 812761, 895987, 929077, 976411, 997057, 1074607, 1125469, 1253887, 1372957, 1609669, 1653919
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OFFSET
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1,1
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LINKS
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FORMULA
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a(n) = x^3-(x-1)^3 where x = A165682(n).
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EXAMPLE
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a(3)= 61=3*5*(5-1)+1 generated by p=3. a(4)=127=3*7*(7-1)+1 generated by p=7. a(5)=331=3*11*(11-1)+1.
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MATHEMATICA
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Select[Table[3 p (p - 1) + 1, {p, Prime[Range[100]]}], PrimeQ] (* Vincenzo Librandi, Sep 13 2013 *)
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PROG
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(Magma) [a: p in PrimesUpTo(1000) | IsPrime(a) where a is 3*p*(p-1)+1]; // Vincenzo Librandi, Sep 13 2013 *
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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