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A133157
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Numbers k such that k^2 + k - 41 is prime.
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1
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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
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OFFSET
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1,1
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LINKS
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EXAMPLE
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If k=8, then k^2 + n - 41 = 31 (prime).
If k=99, then k^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, Jan 08 2008
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MATHEMATICA
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PROG
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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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