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A216148
Primes of the form 2*k^k + 1 = A216147(k).
13
3, 17832200896513, 78692816150593075150849
OFFSET
1,1
COMMENTS
The sequence should be extended through A110932, which lists the corresponding values of k: The next term, 2*251^251 + 1 = A216147(A110932(4)) ~ 4.16*10^602, is too large to include here.
LINKS
C. Caldwell, G.L. Honaker (Eds), Prime Curios!: 78692816150593075150849.
"Jim", Topic: The Lost Proof of Fermat, on mathforum.org, Jan 31 2004
FORMULA
a(2) = A216147(12) = A005109(95) = A070855(12) = A058383(89) = A133663(18).
a(3) = A216147(18) = A005109(183)= A070855(18) = A058383(177)= A133663(36).
MATHEMATICA
Select[Table[2n^n+1, {n, 20}], PrimeQ] (* Harvey P. Dale, Mar 27 2016 *)
PROG
(PARI) for(n=1, 999, ispseudoprime(p=n^n*2+1) & print1(p", "))
CROSSREFS
Cf. A110932.
A subsequence of A133663, with b=a and c=1.
Sequence in context: A275939 A230810 A266199 * A058453 A058471 A068740
KEYWORD
nonn,bref,less
AUTHOR
M. F. Hasler, Sep 02 2012
STATUS
approved