A105764 - OEIS

%I #7 Jun 14 2012 01:24:11

%S 2,3,5,7,8,9,10,13,30,35,77,98,126,160,192,810,1086,1999,2021,3157,

%T 3426,3471,15066,24115,29782,29941

%N Indices of prime Lucas 5-step numbers, A074048.

%C No other n < 30000.

%H Tony D. Noe and Jonathan Vos Post, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL8/Noe/noe5.html">Primes in Fibonacci n-step and Lucas n-step Sequences,</a> J. of Integer Sequences, Vol. 8 (2005), Article 05.4.4

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Lucasn-StepNumber.html">Lucas n-Step Number</a>

%t a={-1, -1, -1, -1, 5}; lst={}; Do[s=Plus@@a; a=RotateLeft[a]; a[[ -1]]=s; If[PrimeQ[s], AppendTo[lst, n]], {n, 30000}]; lst

%Y Cf. A105765 (prime Lucas 5-step numbers).

%K nonn

%O 1,1

%A _T. D. Noe_, Apr 22 2005