s = X3 + X + 1
s = X + 1 (Fibonacci)
j=13
(gj -
i=1j
s4-i ·
gj-i)Xj.
and
Working out the formula for gi with i < 15, and discarding the terms with exponent >14, we find
We read off from this polynomial that g14 = 104g1 + 104g3 + 65g2 + 64g0.
The Fibonacci sequence g0,
g1, g2, g3, ....
is determined by the recurrence
The sequence is only fully determined once we specify the two first numbers:
The sequence can be produced by means of the shift register
with shift polynomial s = X + 1
Z[X].
According to the above formula, with f = a + (b - a)X and t = X + X2, the entry gi is given as the coefficient of Xi in
The alternative name rabbit sequence for the Fibonacci sequence comes from the interpretation of gn as the number of rabbits of a given population in the year n. The recurrence gk+2 = gk+1 + gk is inspired by their reproductive behaviour.