|
|
A182353
|
|
Primes of the form n*2^n - 5.
|
|
3
|
|
|
3, 19, 59, 379, 4603, 1048571, 44040187, 7516192763, 6614661952700411, 13510798882111483, 477381560501272571, 16717361816799281147, 4869940435459321626619, 802726744224113772004900859
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
These are similar to the Woodall primes, A050918, and to sequence A182352, which are primes of the form n*2^n - 1 and of the form n*2^n - 3 respectively. However, this sequence seems to grow rather more slowly than those.
|
|
LINKS
|
|
|
EXAMPLE
|
3 = 2*2^2 - 5; 19 = 3*2^3 - 5; 59 = 4*2^4 - 5.
|
|
MAPLE
|
#choose N large, then S is the desired set
f:=n->n*2^n - 5:
S:={}:
for n from 0 to N do if(isprime(f(n))) then S:=S union {f(n)}: fi: od
|
|
MATHEMATICA
|
Select[Table[n*2^n-5, {n, 2, 100}], PrimeQ] (* Harvey P. Dale, Aug 06 2013 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|