OFFSET
1,2
COMMENTS
These Lucas numbers L(n) have no prime factor congruent to 2 mod 3 to an odd power.
LINKS
V. Raman, Table of n, a(n) for n = 1..109
Blair Kelly, Fibonacci and Lucas factorizations
MATHEMATICA
Select[Range[200], Length[FindInstance[x^2 + 3 y^2 == LucasL[#], {x, y}, Integers]] > 0 &] (* T. D. Noe, Aug 27 2012 *)
PROG
(PARI) for(i=2, 500, a=factorint(fibonacci(i-1)+fibonacci(i+1))~; has=0; for(j=1, #a, if(a[1, j]%3==2&&a[2, j]%2==1, has=1; break)); if(has==0, print(i", ")))
CROSSREFS
KEYWORD
nonn
AUTHOR
V. Raman, Aug 23 2012
STATUS
approved