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Search: id:A124987
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| A124987 |
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Primes of the form 12k+5 generated recursively. Initial prime is 5. General term is a(n)=Min {p is prime; p divides 4+Q^2; Mod[p,12]=5}, where Q is the product of previous terms in the sequence. |
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| 5, 29, 17, 6076229, 1289, 78067083126343039013, 521, 8606045503613, 15837917, 1873731749, 809, 137, 2237, 17729
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Since Q is odd, all prime divisors of 4+Q^2 are congruent to 1 modulo 4.
At least one prime divisor of 4+Q^2 is congruent to 2 modulo 3 and hence to 5 modulo 12.
The first two terms are the same as those of A057208.
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LINKS
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N. Hobson, Home page (listed in lieu of email address)
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EXAMPLE
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a(3) = 17 is the smallest prime divisor congruent to 5 mod 12
of 4+Q^2 = 21029 = 17 * 1237, where Q = 5 * 29.
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CROSSREFS
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Cf. A000945, A040117, A057204-A057208, A051308-A051335, A124984-A124993, A125037-A125045.
Sequence in context: A033503 A057206 A057713 this_sequence A002584 A001990 A043062
Adjacent sequences: A124984 A124985 A124986 this_sequence A124988 A124989 A124990
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KEYWORD
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more,nonn
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AUTHOR
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Nick Hobson Nov 18 2006
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