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A074966
a(n) = least k such that n^n + k is prime.
10
1, 1, 2, 1, 12, 7, 4, 43, 10, 19, 62, 35, 16, 27, 28, 13, 74, 107, 18, 91, 32, 87, 14, 95, 96, 43, 68, 135, 120, 19, 58, 7, 58, 63, 54, 31, 42, 115, 10, 157, 110, 13, 4, 403, 122, 457, 534, 37, 18, 31, 226, 253, 20, 193, 102, 177, 392, 45, 194, 257, 102, 79, 454, 231, 306
OFFSET
1,3
COMMENTS
"Are there any n except 1, 2 and 4 that make n^n + 1 a prime? He [SierpiƄski] has shown that if such a prime exists it is greater than 10^30000." - Ogilvy and Anderson
REFERENCES
C. Stanley Ogilvy and John T. Anderson, Excursions in Number Theory. Dover. New York: 1988. Page 82.
LINKS
Hans Havermann and Seiichi Manyama, Table of n, a(n) for n = 1..2500 (Seiichi Manyama to 500)
MATHEMATICA
Array[Block[{k = 1}, While[! PrimeQ[k + #], k++]; k] &[#^#] &, 65] (* Michael De Vlieger, Jul 06 2018 *)
PROG
(PARI) a(n)=(x->nextprime(x)-x)(n^n) \\ Charles R Greathouse IV, Nov 25 2014
CROSSREFS
Sequence in context: A372508 A257635 A085752 * A128413 A058843 A343861
KEYWORD
nonn
AUTHOR
Zak Seidov, Oct 03 2002
EXTENSIONS
More terms from Robert G. Wilson v, Oct 04 2002
Name taken from Comments section by Jon E. Schoenfield, Jan 14 2015
STATUS
approved