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Search: id:A162471
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| A162471 |
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Prime divisors of {n^2+n+1} which do not occur in that sequence. See A002383. |
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+0
3
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| 19, 37, 61, 67, 79, 97, 103, 109, 127, 139, 151, 163, 181, 193, 199
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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19 divides n^2+n+1 for n = 7, 11, 26, 30 ,..., etc. The first pair of first differences of multiples of 19 sum to 19, a pattern which holds for all prime divisors of n^2+n+1 (conjecture) except for 3 (every third element of {n^2+n+1} is divisible by 3).
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EXAMPLE
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The first prime divisor of {n^2+n+1} which is not an element of the sequence A002383 is 19. 7^2+7+1 = 57 = 19*3.
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CROSSREFS
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A002383
Sequence in context: A109639 A161705 A131600 this_sequence A124268 A154944 A039321
Adjacent sequences: A162468 A162469 A162470 this_sequence A162472 A162473 A162474
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KEYWORD
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nonn
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AUTHOR
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Daniel Tisdale (daniel6874(AT)gmail.com), Jul 04 2009
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