

A106279


Primes p such that the polynomial x^3x^2x1 mod p has 3 distinct zeros.


5



47, 53, 103, 163, 199, 257, 269, 311, 397, 401, 419, 421, 499, 587, 599, 617, 683, 757, 773, 863, 883, 907, 911, 929, 991, 1021, 1087, 1109, 1123, 1181, 1237, 1291, 1307, 1367, 1433, 1439, 1543, 1567, 1571, 1609, 1621, 1697, 1699, 1753, 1873, 1907, 2003
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OFFSET

1,1


COMMENTS

This polynomial is the characteristic polynomial of the Fibonacci and Lucas 3step sequences, A000073 and A001644. The periods of the sequences A000073(k) mod p and A001644(k) mod p have length less than p. For a given p, let the zeros be a, b and c. Then A001644(k) mod p = (a^k+b^k+c^k) mod p. This sequence is the same as A033209 except for the initial term.


LINKS

Table of n, a(n) for n=1..47.
Eric Weisstein's World of Mathematics, Fibonacci nStep


MATHEMATICA

t=Table[p=Prime[n]; cnt=0; Do[If[Mod[x^3x^2x1, p]==0, cnt++ ], {x, 0, p1}]; cnt, {n, 500}]; Prime[Flatten[Position[t, 3]]]


CROSSREFS

Cf. A106276 (number of distinct zeros of x^3x^2x1 mod prime(n)), A106294, A106302 (periods of the Fibonacci and Lucas 3step sequences mod prime(n)).
Sequence in context: A243431 A141279 A155139 * A275022 A048581 A169716
Adjacent sequences: A106276 A106277 A106278 * A106280 A106281 A106282


KEYWORD

nonn


AUTHOR

T. D. Noe, May 02 2005


STATUS

approved



