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.
2, 3, 3, 3, 3, 3389, 63559
Offset: 0
Examples
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.
Extensions
a(6) from Max Alekseyev, Feb 14 2017