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A046849
Numbers k such that k*2^k+(k-1) is prime.
1
1, 4, 6, 30, 34, 94, 216, 1120, 1438, 3370, 5062, 6714, 30666, 36966
OFFSET
1,2
COMMENTS
The corresponding primes are given in A046848.
MATHEMATICA
Select[Range[10^4], PrimeQ[#*2^# + (# - 1)] &] (* Michael De Vlieger, Mar 02 2015 *)
PROG
(PARI) isok(n) = isprime(n*2^n+(n-1)); \\ Michel Marcus, Oct 12 2014
(PARI) for(n=1, 10^6, if(ispseudoprime(n*2^n+(n-1)), print1(n, ", "))); \\ Joerg Arndt, Mar 02 2015
CROSSREFS
Cf. A046848.
Sequence in context: A259087 A364737 A056221 * A090530 A154667 A376482
KEYWORD
hard,more,nonn
AUTHOR
EXTENSIONS
a(8)-a(9) from Michel Marcus, Oct 12 2014
a(10)-a(12) (pseudoprimes) from Joerg Arndt, Mar 02 2015
a(13)-a(14) from Michael S. Branicky, Jan 21 2023
STATUS
approved