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A246516
Primes of the form 2*4^n - n.
0
2, 7, 549755813869, 2475880078570760549798248403
OFFSET
1,1
COMMENTS
a(5) and a(6) are 125 and 266 decimal digits long, respectively. - Derek Orr, Aug 28 2014
EXAMPLE
2*4^0 - 0 = 2 is prime, thus 2 is a member of this sequence.
MATHEMATICA
Select[Table[2^(2n + 1) - n, {n, 0, 127}], PrimeQ] (* Alonso del Arte, Sep 16 2014 *)
PROG
(Magma) [a: n in [0..500] | IsPrime(a) where a is 2*4^n - n];
(PARI)
for(n=0, 10^3, if(ispseudoprime(2^(2*n+1)-n), print1(2^(2*n+1)-n, ", "))) \\ Derek Orr, Aug 28 2014
CROSSREFS
Sequence in context: A153089 A077548 A050809 * A095217 A230915 A242922
KEYWORD
nonn
AUTHOR
STATUS
approved