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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). 0
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

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

LINKS

Table of n, a(n) for n=1..57.

EXAMPLE

a(1) = 3 because 3^128+1 = 2

* 257 * 275201 * 138424618868737 * 3913786281514524929 * 153849834

853910661121  with A208178(1) = 257.

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

CROSSREFS

Cf. A208178.

Sequence in context: A106877 A041949 A222452 * A102329 A331713 A327321

Adjacent sequences:  A218162 A218163 A218164 * A218166 A218167 A218168

KEYWORD

nonn

AUTHOR

Michel Lagneau, Oct 22 2012

STATUS

approved

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Last modified August 4 05:02 EDT 2021. Contains 346442 sequences. (Running on oeis4.)