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

0,1

Links

Table of n, a(n) for n=0..6.

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

Adjacent sequences: A282349 A282350 A282351 * A282353 A282354 A282355

Keyword

nonn,more

Author

Altug Alkan, Feb 12 2017

Extensions

a(6) from Max Alekseyev, Feb 14 2017

Status

approved