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A282352
Smallest value of x + y such that x^(2^k) + y^(2^k) is prime for every k = 0..n, where x > y are nonnegative integers.
1
2, 3, 3, 3, 3, 3389, 63559
OFFSET
0,1
EXAMPLE
a(0) = 2 because 2^(2^0) + 0^(2^0) = 2.
a(1) = 3 because 2^(2^0) + 1^(2^0) = 3 and 2^(2^1) + 1^(2^1) = 5 are prime.
a(2) = 3 because 2^(2^0) + 1^(2^0) = 3, 2^(2^1) + 1^(2^1) = 5, and 2^(2^2) + 1^(2^2) = 17 are prime.
a(n) x y
----- ----- -----
2 2 0
3 2 1
3 2 1
3 2 1
3 2 1
3389 2669 720
63559 34559 29000
CROSSREFS
Cf. A111635.
Sequence in context: A089336 A089335 A088093 * A256858 A049837 A326202
KEYWORD
nonn,more
AUTHOR
Altug Alkan, Feb 12 2017
EXTENSIONS
a(6) from Max Alekseyev, Feb 14 2017
STATUS
approved