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A162487 Values of y for A094133: primes of the form x^y+y^x, x>y>1 3
2, 2, 2, 2, 2, 5, 3, 15, 7, 33 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

See A094133 for links, references and more information.

Whereas a list of the possible x-values can be established by a brute-force search, this is not possible for the y-values. Some, however, may easily be excluded. For example, 4 cannot occur in this sequence, since for even y, x must be odd, and for x = 2k - 1, x^4 + 4^x = (x^2 + 2^k*x + 2^x)(x^2 - 2^k*x + 2^x).

LINKS

Table of n, a(n) for n=1..10.

FORMULA

A094133(n)=A162486(n)^A162487(n)+A162487(n)^A162486(n)

CROSSREFS

Sequence in context: A180214 A263342 A089452 * A215924 A115101 A241148

Adjacent sequences:  A162484 A162485 A162486 * A162488 A162489 A162490

KEYWORD

more,nonn

AUTHOR

M. F. Hasler, Jul 04 2009

STATUS

approved

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Last modified April 20 08:50 EDT 2019. Contains 322306 sequences. (Running on oeis4.)