A218165 a(n) is the smallest positive integer k such that k^128 + 1 == 0 mod p, where p is the n-th prime of the form 1 + 256*b (see A208178).

3, 7, 17, 198, 71, 88, 29, 50, 9, 225, 26, 141, 10, 79, 36, 89, 281, 108, 43, 233, 156, 412, 430, 296, 79, 20, 76, 178, 80, 54, 1018, 82, 89, 403, 85, 208, 914, 373, 1226, 62, 192, 68, 390, 1055, 1500, 137, 1018, 141, 95, 54, 160, 52, 11, 754, 674, 182, 517

Offset: 1

Author

Michel Lagneau, Oct 22 2012

Keywords

• nonn

Comments

A208178(n): primes of form 256n+1.

Examples

			a(1) = 3 because 3^128+1 = 2
* 257 * 275201 * 138424618868737 * 3913786281514524929 * 153849834
853910661121  with A208178(1) = 257.
		

Crossrefs

Cf. A208178.

Programs

Mathematica

aa = {}; Do[p = Prime[n]; If[Mod[p, 256] == 1, k = 1; While[ ! Mod[k^128 + 1, p] == 0, k++ ]; AppendTo[aa, k]], {n, 5000}]; aa