A235868 Union of 2 and powers of odd primes.

1, 2, 3, 5, 7, 9, 11, 13, 17, 19, 23, 25, 27, 29, 31, 37, 41, 43, 47, 49, 53, 59, 61, 67, 71, 73, 79, 81, 83, 89, 97, 101, 103, 107, 109, 113, 121, 125, 127, 131, 137, 139, 149, 151, 157, 163, 167, 169, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229

Offset: 1

Author

José María Grau Ribas, Feb 23 2014

Keywords

• nonn

Comments

Numbers n such that the group G_n:={x+yi: x^2+y^2==1 (mod n); 0<=x,yA060968(n) = A235863(n).

Links

• Jose María Grau, A. M. Oller-Marcen, Manuel Rodriguez and D. Sadornil, Fermat test with Gaussian base and Gaussian pseudoprimes, arXiv:1401.4708 [math.NT], 2014.

Crossrefs

Cf. A060968, A061345, A235863.

Programs

Mathematica

Select[ Range[230], # == 2 || Mod[#, 2] == 1 && PrimeNu[#] < 2 &] (* and modified by Robert G. Wilson v, Dec 29 2016 *)

Formula

{2} UNION A061345. - R. J. Mathar, Jul 19 2024