A253705 Indices of primes in the 8th-order Fibonacci number sequence, A079262.

9, 17, 25, 125, 350, 1322, 108935, 199528

Offset

1,1

Comments

a(9) > 2*10^5.

Links

Table of n, a(n) for n=1..8.

Tony D. Noe and Jonathan Vos Post, Primes in Fibonacci n-step and Lucas n-step Sequences, J. of Integer Sequences, Vol. 8 (2005), Article 05.4.4

Mathematica

a={0, 0, 0, 0, 0, 0, 0, 1}; step=8; lst={}; For[n=step, n<=1000, n++, sum=Plus@@a; If[PrimeQ[sum], AppendTo[lst, n]]; a=RotateLeft[a]; a[[step]]=sum]; lst
Flatten[Position[LinearRecurrence[{1, 1, 1, 1, 1, 1, 1, 1}, {0, 0, 0, 0, 0, 0, 0, 1}, 200000], _?PrimeQ]]-1 (* The program takes a long time to run *) (* Harvey P. Dale, Apr 26 2018 *)

Prog

(PARI) lista(nn) = {gf = x^7/(1-x-x^2-x^3-x^4-x^5-x^6-x^7-x^8); for (n=0, nn, if (isprime(polcoeff(gf+O(x^(n+1)), n)), print1(n, ", ")); ); } \\ Michel Marcus, Jan 12 2015

Crossrefs

Cf. A001590, A001631, A100683, A231574, A231575, A232542, A214899, A230607, A020992, A232498, A214727, A081172, A214752, A141523, A214825, A235862, A000288, A000322, A000383, A249413, A060455, A079262.

Sequence in context: A211422 A035198 A271186 * A056233 A260264 A126623

Adjacent sequences: A253702 A253703 A253704 * A253706 A253707 A253708

Keyword

nonn,more

Author

Robert Price, Jan 09 2015

Status

approved