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A180269
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Primes of the form 3^n+3*n+1.
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3
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2, 7, 37, 36472996377170786527, 2954312706550833698779, 3990838394187339929534246675572349035477, 2120895147045314119491609587512844743630072393, 228532044137599177017869183161846685251274404207185590172004697234871412029099114059347
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OFFSET
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1,1
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COMMENTS
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Terms a(9) through a(12) have, respectively, 93, 94, 149, and 156 digits. - Harvey P. Dale, May 11 2013
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LINKS
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MATHEMATICA
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Select[Table[3^n+3n+1, {n, 0, 100}], PrimeQ] (* Harvey P. Dale, May 11 2013 *)
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PROG
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(PARI) for(i=0, 200, x=3^i+3*i+1; if(isprime(x), print1(x", ")))
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CROSSREFS
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KEYWORD
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hard,nonn
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AUTHOR
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Graziano Aglietti (mg5055(AT)mclink.it), Aug 23 2010
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EXTENSIONS
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STATUS
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approved
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