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A162490
Least prime of the form x^y+y^x with x = A162488(n) > y > 1.
5
17, 593, 32993, 2097593, 59604644783353249, 43143988327398957279342419750374600193, 8589935681, 5052785737795758503064406447721934417290878968063369478337
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.
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, i-1, isprime(i^j+j^i)|next; print1(i^j+j^i", "); break))
CROSSREFS
KEYWORD
nonn
AUTHOR
M. F. Hasler, Jul 04 2009
STATUS
approved