Search: id:A106278 Results 1-1 of 1 results found. %I A106278 %S A106278 1,0,0,0,0,0,0,1,2,1,0,0,0,2,3,0,2,3,1,0,1,0,0,1,1,1,1,0,1,3,1,2,3,1,1, %T A106278 0,0,1,1,1,1,1,1,3,1,0,1,1,1,0,0,0,0,1,0,0,2,1,0,0,3,3,1,0,1,0,0,0,1,1, %U A106278 1,2,1,2,0,2,0,1,1,0,1,2,0,0,2,2,1,1,2,0,0,2,1,2,2,2,1,0,0,0,0,0,0,1,0 %N A106278 Number of distinct zeros of x^5-x^4-x^3-x^2-x-1 mod prime(n). %C A106278 This polynomial is the characteristic polynomial of the Fibonacci and Lucas 5-step sequences, A001591 and A074048. Similar polynomials are treated in Serre's paper. The discriminant of the polynomial is 9584=16*599 and 599 is the only prime for which the polynomial has 4 distinct zeros. The primes p yielding 5 distinct zeros, A106281, correspond to the periods of the sequences A001591(k) mod p and A074048(k) mod p having length less than p. The Lucas 5-step sequence mod p has one additional prime p for which the period is less than p: the 599 factor of the discriminant. For this prime, the Fibonacci 5-step sequence mod p has a period of p(p-1). %H A106278 J.-P. Serre, On a theorem of Jordan, Bull. Amer. Math. Soc., 40 (No. 4, 2003), 429-440, see p. 433. %H A106278 Eric Weisstein's World of Mathematics, Fibonacci n-Step %t A106278 Table[p=Prime[n]; cnt=0; Do[If[Mod[x^5-x^4-x^3-x^2-x-1, p]==0, cnt++ ], {x, 0, p-1}]; cnt, {n, 150}] %Y A106278 Cf. A106298 (period of the Lucas 5-step sequences mod prime(n)), A106284 (prime moduli for which the polynomial is irreducible). %Y A106278 Sequence in context: A004198 A116402 A093323 this_sequence A064287 A128206 A103294 %Y A106278 Adjacent sequences: A106275 A106276 A106277 this_sequence A106279 A106280 A106281 %K A106278 nonn %O A106278 1,9 %A A106278 T. D. Noe (noe(AT)sspectra.com), May 02 2005 Search completed in 0.001 seconds