|
| |
|
|
A050918
|
|
Woodall primes: primes of form n*2^n-1.
|
|
14
|
|
|
|
7, 23, 383, 32212254719, 2833419889721787128217599, 195845982777569926302400511, 4776913109852041418248056622882488319, 1307960347852357218937346147315859062783, 225251798594466661409915431774713195745814267044878909733007331390393510002687
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
LINKS
|
M. F. Hasler, Table of n, a(n) for n = 1..15 (all terms < 10^999).
Ray Ballinger, Woodall Primes: Definition and Status
C. K. Caldwell, Woodall Numbers
Brady Haran and Matt Parker, 383 is cool - Numberphile (2017)
Eric Weisstein's World of Mathematics, Woodall Numbers
|
|
|
FORMULA
|
a(n) = A002234(n)*2^A002234(n) - 1. - M. F. Hasler, May 10 2017
|
|
|
MATHEMATICA
|
Select[Table[n 2^n-1, {n, 300}], PrimeQ] (* Harvey P. Dale, Jul 12 2012 *)
|
|
|
PROG
|
(PARI) for(n=2, 999, ispseudoprime(p=n*2^n-1)&&print1(p", ")) \\ M. F. Hasler, May 10 2017
|
|
|
CROSSREFS
|
Cf. A002234, A003261.
Sequence in context: A099051 A187487 A034192 * A228699 A159485 A009047
Adjacent sequences: A050915 A050916 A050917 * A050919 A050920 A050921
|
|
|
KEYWORD
|
nonn,easy,nice
|
|
|
AUTHOR
|
N. J. A. Sloane, Dec 30 1999
|
|
|
STATUS
|
approved
|
| |
|
|
