OFFSET
1,2
COMMENTS
Noe and Post conjectured that the only positive terms that are common to any two distinct n-step Lucas sequences are the Mersenne numbers (A001348) that begin each sequence and 7 and 11 (in 2- and 3-step) and 5071 (in 3- and 4-step). The intersection of this sequence with the union of all the n-step Fibonacci sequences (A124168) appears to consist of 4, 21, 29, the Mersenne numbers 2^n-1 for all n and the infinite set of Eulerian numbers in A127232.
LINKS
T. D. Noe, Table of n, a(n) for n=1..1000
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
LucasSequence[n_, kMax_] := Module[{a, s, lst={}}, a=Join[Table[ -1, {n-1}], {n}]; While[s=Plus@@a; a=RotateLeft[a]; a[[n]]=s; s<=kMax, AppendTo[lst, s]]; lst]; nn=10; t={}; Do[t=Union[t, LucasSequence[n, 2^(nn+1)]], {n, 2, nn}]; t
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe, Jan 09 2007
STATUS
approved