A160044 Nonnegative integers x such that x^y+y^x is not prime for any integer y>1, y<x.

0, 1, 2, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20, 22, 23, 25, 26, 27, 28, 29, 30, 31, 34, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 55, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 70, 71, 72, 73, 74, 77, 78, 79, 80, 82, 83, 84, 85, 86

Offset

1,3

Comments

This lists the nonnegative integers not occurring in A162486, i.e. the complement of A162488.

See A094133 for more information, links and references.

Links

Table of n, a(n) for n=1..72.

Prog

(PARI) for( i=0, 999, for( j=2, i-1, is/*pseudo*/prime(i^j+j^i) && next(2)); print1(i", "))

Crossrefs

Cf. A094133, A162486 - A162490.

Sequence in context: A184528 A047263 A039244 * A180917 A127428 A039187

Adjacent sequences: A160041 A160042 A160043 * A160045 A160046 A160047

Keyword

nonn

Author

M. F. Hasler, Jul 04 2009

Status

approved