

A300478


Numbers n where more than one positive integer k with 1 < k < n exists such that n^k + k^n is prime.


1



114, 318, 590, 790, 903, 1036, 1158, 1263, 1298, 1545, 1588
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

Numbers n such that A300477(n) > 1.
Subsequence of A162488.


LINKS

Table of n, a(n) for n=1..11.


EXAMPLE

114 is a term of the sequence, since 114^k + k^114 is prime for two values of k with 1 < k < 114, namely, k=67 and k=97.


PROG

(PARI) a300477(n) = my(i=0); for(k=2, n1, if(ispseudoprime(n^k+k^n), i++)); i
is(n) = a300477(n) > 1


CROSSREFS

Cf. A162488, A300477.
Sequence in context: A171374 A228962 A250725 * A305066 A322541 A323758
Adjacent sequences: A300475 A300476 A300477 * A300479 A300480 A300481


KEYWORD

nonn,hard,more


AUTHOR

Felix FrÃ¶hlich, Mar 06 2018


EXTENSIONS

a(7)a(11) from Robert Israel, Sep 25 2020


STATUS

approved



