

A162490


Least prime of the form x^y+y^x with x = A162488(n) > y > 1.


5




OFFSET

1,1


COMMENTS

Sequences A162488 and A162489 list the corresponding x and y values.
Sequence A094133 lists these primes ordered by their size (without multiplicity). See there for more information, links and references.


LINKS

Table of n, a(n) for n=1..8.


FORMULA

a(n) = A162488(n)^A162489(n) + A162489(n)^A162488(n)


EXAMPLE

The least x such that x^y+y^x is prime for some x>y>1 is A162488(1)=3, for y=A162489(1)=2, yielding the prime a(1) = 9 + 8 = 17.


PROG

(PARI) for(i=3, 999, for(j=2, i1, isprime(i^j+j^i)next; print1(i^j+j^i", "); break))


CROSSREFS

Cf. A094133, A162486  A162489.
Sequence in context: A041544 A202407 A009709 * A296790 A142744 A219090
Adjacent sequences: A162487 A162488 A162489 * A162491 A162492 A162493


KEYWORD

nonn


AUTHOR

M. F. Hasler, Jul 04 2009


STATUS

approved



