|
Search: id:A124985
|
|
|
| A124985 |
|
Primes of the form 8k+7 generated recursively. Initial prime is 7. General term is a(n)=Min {p is prime; p divides 16Q^2-2; Mod[p,8]=7}, where Q is the product of previous terms in the sequence. |
|
+0
1
|
|
| 7, 23, 207367, 1902391, 167, 1511, 28031, 79, 3142977463, 2473230126937097422987916357409859838765327
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
16Q^2-2 always has a prime divisor congruent to 7 modulo 8.
|
|
REFERENCES
|
D. M. Burton, Elementary Number Theory, McGraw-Hill, Sixth Edition (2007), p. 182.
|
|
LINKS
|
N. Hobson, Home page (listed in lieu of email address)
|
|
EXAMPLE
|
a(4) = 1902391 is the smallest prime divisor congruent to 7 mod
8 of 16Q^2-2 = 17834092882745102 = 2 * 97 * 1902391 * 48322513, where Q =
7 * 23 * 207367.
|
|
CROSSREFS
|
Cf. A000945, A007522, A057204-A057208, A051308-A051335, A124984-A124993, A125037-A125045.
Sequence in context: A009047 A129662 A012482 this_sequence A126612 A070410 A077035
Adjacent sequences: A124982 A124983 A124984 this_sequence A124986 A124987 A124988
|
|
KEYWORD
|
more,nonn
|
|
AUTHOR
|
Nick Hobson Nov 18 2006
|
|
|
Search completed in 0.002 seconds
|
