OFFSET
1,1
COMMENTS
Numbers k such that A185277(k) is prime.
LINKS
Hans Havermann, Indices of A094133 in A076980.
Andrey V. Kulsha, Factorizations of x^y + y^x for 1 < y < x < 151.
P. Leyland, Primes and Strong Pseudoprimes of the form x^y + y^x.
EXAMPLE
2 is a term of the sequence, because A185277(2) = 593 is prime.
PROG
(PARI) is(n) = ispseudoprime(n^9+9^n)
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Felix Fröhlich, Aug 27 2016
STATUS
approved