

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
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,3


COMMENTS

"Are there any n except 1, 2 and 4 that make n^n + 1 a prime? He [SierpiĆski] 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

Cf. A055385, A074967.
Sequence in context: A010255 A257635 A085752 * A128413 A058843 A130559
Adjacent sequences: A074963 A074964 A074965 * A074967 A074968 A074969


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



