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A124990 Primes of the form 12k+1 generated recursively. Initial prime is 13. General term is a(n)=Min {p is prime; p divides Q^4-Q^2+1}, where Q is the product of previous terms in the sequence. +0
2
13, 28393, 128758492789, 73, 193, 37, 457 (list; graph; listen)
OFFSET

1,1

COMMENT

All prime divisors of Q^4-Q^2+1 are congruent to 1 modulo 12.

REFERENCES

K. Ireland and M. Rosen, A Classical Introduction to Modern Number Theory, Springer-Verlag, NY, Second Edition (1990), p. 63.

LINKS

N. Hobson, Home page (listed in lieu of email address)

EXAMPLE

a(3) = 128758492789 is the smallest prime divisor of Q^4-Q^2+1

= 18561733755472408508281 = 128758492789 * 144159296629, where Q = 13 *

28393.

CROSSREFS

Cf. A000945, A068228, A057204-A057208, A051308-A051335, A124984-A124993, A125037-A125045.

Sequence in context: A098562 A123921 A145716 this_sequence A013752 A076811 A048917

Adjacent sequences: A124987 A124988 A124989 this_sequence A124991 A124992 A124993

KEYWORD

more,nonn

AUTHOR

Nick Hobson Nov 18 2006

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


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