To be more precise: F + 1 = F L F + 1 = F L 4n 2n-1 2n+1 4n+1 2n+1 2n F + 1 = F L F + 1 = F L 4n+2 2n+2 2n 4n+3 2n+1 2n+2 R. On Thu, 27 Feb 2003, Floor en Lyanne van Lamoen wrote: > L.S. > > Is there a good reason why the entries of A001611 (Fibonacci(n) + 1) > after the initial 1,2,2,3 are all composite? Or is this perhaps not > true? > > Sincerely, > Floor. >