A207261 Primes of the form x^(2*y) + y^(2*x), for x and y > 1.

10657, 274200257, 304606801, 92205451297, 22876799984497, 1853020205629057, 59604706692754849, 523348059906214747850254177, 144226335084562589858781936977, 25053659285408524696023221081716801, 100000000000037589973457545958193355601

Offset

1,1

Comments

If x or y = 1, we obtain primes of the form x^2 + 1 (or y^2 + 1) corresponding to the sequence A002496(n). The first value of this sequence, a(1) = 10657, is not of the form x^2 + 1.

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..50

Example

10657 is in the sequence because if (x,y) = (3,4), then 3^(2*4) + 4^(2*3) = 6561 + 4096 = 10657.

Mathematica

a={}; Do[Do[k=x^(2*y)+y^(2*x); If[PrimeQ[k], AppendTo[a, k]], {x, 2, y}], {y, 2, 200}]; Union[a]

Crossrefs

Cf. A002496, A094133, A111635.

Sequence in context: A138254 A154510 A157326 * A250524 A251062 A238150

Adjacent sequences: A207258 A207259 A207260 * A207262 A207263 A207264

Keyword

nonn

Author

Michel Lagneau, Feb 16 2012

Status

approved