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A110932
Numbers k such that 2*k^k + 1 is prime.
11
0, 1, 12, 18, 251, 82992
OFFSET
0,3
COMMENTS
As a "list of numbers such that ...", the sequence should have offset 1, but to preserve the validity of formulas referring to this sequence, the offset was set to 0 when the initial value a(0)=0 was added. - M. F. Hasler, Sep 02 2012
MATHEMATICA
Join[{0}, Select[Range[1000], PrimeQ[2*#^# + 1] &]] (* Robert Price, Mar 27 2019 *)
PROG
(PARI) is_A110932(n)=ispseudoprime(n^n*2+1) \\ M. F. Hasler, Sep 02 2012
CROSSREFS
Cf. A110931, A121270 (= primes in A014566), A088790, A160360, A160600.
The primes 2n^n+1, for k<4, n=a(k)<251, are listed at A216148(k) = A216147(a(k)). - M. F. Hasler, Sep 02 2012
Sequence in context: A018957 A238922 A212128 * A112880 A211083 A100541
KEYWORD
nonn,hard,more
AUTHOR
Ray G. Opao, Sep 25 2005
EXTENSIONS
a(5) from Serge Batalov, Apr 08 2018
STATUS
approved