OFFSET
1,2
COMMENTS
Prove that 17 is the only prime which is the average of two consecutive Fibonacci numbers.
MATHEMATICA
f[n_] := Fibonacci[n]; a = Select[ Range[70], IntegerQ[(f[ # ] + f[ # + 1])/2] && !PrimeQ[(f[ # ] + f[ # + 1])/2] &]; (f[a] + f[a + 1])/2
CROSSREFS
KEYWORD
nonn
AUTHOR
G. L. Honaker, Jr., Jun 22 2002
EXTENSIONS
Edited by Robert G. Wilson v, Jun 27 2002
STATUS
approved