1,1

For a prime p congruent to 1 mod 16, the number 2 is an octavic residue mod p if and only if there are integers x and y such that x^2 + 256*y^2 = p.

Table of n, a(n) for n=1..42.

Index entries for related sequences

Subsequence of A045315.

Sequence in context: A062382 A289560 A256776 * A105345 A060261 A264348

Adjacent sequences: A252276 A252277 A252278 * A252280 A252281 A252282

nonn

Arkadiusz Wesolowski, Dec 16 2014

approved