def fib(n):
if n < 2: return 1
else : return fib(n - 1) + fib(n - 2)
if n < 2: return n
...Or am I being stupid?
EDIT: changed x to n.
However, it's certainly different to the other examples and I would expect fib(2) to be 1 + 0 not 1 + 1.
It's a very minor point though - I think I'll stop now ;)
fib(2) = fib(2-1) + fib(2-2)
fib(2) = fib(1) + fib(0)
fib(2) = 1 + 1 (rather than 1 + 0)
No?
By definition, the first two Fibonacci numbers are 0
and 1, and each subsequent number is the sum of the
previous two. Some sources omit the initial 0, instead
beginning the sequence with two 1s.EDIT: Actually, I think you're right: it's just an index thing (do we start at 1 or 0) - I was confusing the index of 2 with the value of 2.