OFFSET
3,4
COMMENTS
For clarification: if the largest prime factor occurs more than once, then that prime factor is selected.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 3..1422
EXAMPLE
F(82) = 2789 * 59369 * 370248451, so a(82) = 59369.
MATHEMATICA
factors[n_] := Flatten[Table[#[[1]], {#[[2]]}] & /@ FactorInteger[n]]; fn[n_] := Module[{fibn = Fibonacci[n]}, If[PrimeQ[fibn], 1, factors[fibn][[-2]]]]; Table[fn[n], {n, 3, 80}]
PROG
(PARI) a(n)=my(f=factor(fibonacci(n)), t=#f[, 1]); if(f[t, 2]==1, if(t==1, 1, f[t-1, 1]), f[t, 1])
CROSSREFS
KEYWORD
nonn
AUTHOR
Charles R Greathouse IV, Jul 31 2011
STATUS
approved