|
Search: id:A065918
|
|
| |
|
| 1, 3, 1, 6, 9, 5, 7, 8, 9, 6, 9, 2, 4, 8, 1, 6, 7, 0, 8, 6, 2, 5, 0, 4, 6, 3, 4, 7, 3, 0, 7, 9, 6, 8, 4, 4, 4, 0, 2, 6, 9, 8, 1, 9, 7, 1, 4, 6, 7, 5, 1, 6, 4, 7, 9, 7, 6, 8, 4, 7, 2, 2, 5, 6, 9, 2, 0, 4, 6, 0, 1, 8, 5, 4, 1, 6, 4, 4, 3, 9, 7, 6, 0, 7, 4, 2, 1, 9, 0, 1, 3, 4, 5, 0, 1, 0, 1, 7, 8, 3, 5, 5
(list; cons; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
x = 2^n -1 is prime if and only if x divides cosh( 2^(n-2) * ln(2+sqrt(3))).
|
|
LINKS
|
Harry J. Smith, Table of n, a(n) for n=1,...,2000
Chris Caldwell, Primality Proving, Arndt's theorem.
|
|
EXAMPLE
|
1.316957896924816708625046347307968444...
|
|
PROGRAM
|
(PARI) { default(realprecision, 2080); x=log(2 + sqrt(3)); for (n=1, 2000, d=floor(x); x=(x-d)*10; write("b065918.txt", n, " ", d)) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Nov 04 2009]
|
|
CROSSREFS
|
Cf. A001075.
Sequence in context: A013610 A008573 A089710 this_sequence A020861 A163213 A095066
Adjacent sequences: A065915 A065916 A065917 this_sequence A065919 A065920 A065921
|
|
KEYWORD
|
nonn,easy,cons,new
|
|
AUTHOR
|
Frank.Ellermann(AT)t-online.de, Dec 08 2001
|
|
|
Search completed in 0.002 seconds
|
