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Search: id:A133157
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| A133157 |
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Numbers n such that n^2 + n - 41 is prime. |
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+0
2
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| 8, 15, 20, 21, 26, 29, 36, 45, 48, 59, 68, 69, 75, 78, 98, 99, 108, 111, 113, 120, 129, 134, 138, 140, 143, 161, 168, 185, 188, 189, 210, 213, 215, 216, 218, 224, 230, 231, 234, 251, 255, 260, 266, 273, 278, 279, 281, 290, 294, 299, 306, 308, 314, 320, 329, 356
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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If n=8, then n^2 + n - 41 = 31 (prime)
If n=99, then n^2 + n - 41 = 9859 (prime)
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MAPLE
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isA133157 := proc(n) isprime(n*(n+1)-41) ; end: for n from 1 to 400 do if isA133157(n) then printf("%d, ", n) ; fi ; od: - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 08 2008
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MATHEMATICA
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Select[Range[7, 400], PrimeQ[ #^2 + # - 41] &] - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Dec 24 2007
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CROSSREFS
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Cf. A002837.
Sequence in context: A126852 A114605 A031103 this_sequence A014544 A122754 A082867
Adjacent sequences: A133154 A133155 A133156 this_sequence A133158 A133159 A133160
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KEYWORD
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nonn
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AUTHOR
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Parthasarathy Nambi (PachaNambi(AT)yahoo.com), Dec 17 2007
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EXTENSIONS
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More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Dec 24 2007
More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 08 2008
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