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Search: id:A154115
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| A154115 |
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Numbers n such that (n+2)^2-(n+1)^2-n is prime. |
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1
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| 2, 4, 8, 10, 14, 16, 20, 26, 28, 34, 38, 40, 44, 50, 56, 58, 64, 68, 70, 76, 80, 86, 94, 98, 100, 104, 106, 110, 124, 128, 134, 136, 146, 148, 154, 160, 164, 170, 176, 178, 188, 190, 194, 196, 208, 220, 224, 226, 230, 236, 238, 248, 254, 260, 266, 268, 274, 278
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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4^2-3^2-2=5,...
Since (n+2)^2-(n+1)^2-n = n+3, this is just the primes minus 3 (starting with p=5, since apparently only positive integers are being included). [From Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Jan 30 2009]
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MATHEMATICA
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a[n_]:=(n+2)^2-(n+1)^2-n; lst={}; Do[If[PrimeQ[a[n]], AppendTo[lst, n]], {n, 6!}]; lst
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CROSSREFS
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Cf. A140719, A005097, A154111, A154112, A154113
Cf. A067076 (a(n-1)/2). [From Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Jan 30 2009]
Sequence in context: A047235 A087505 A086801 this_sequence A071703 A010069 A132895
Adjacent sequences: A154112 A154113 A154114 this_sequence A154116 A154117 A154118
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KEYWORD
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nonn
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AUTHOR
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Vladimir Orlovsky (4vladimir(AT)gmail.com), Jan 04 2009
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