Question

Find the first five terms of the sequence described by the following recursive formula: an = an – 1 + an – 2 where a1 = 1.2 and a2 = 2.3
1.2, , , ,


Find the first six terms of the sequence described by the following recursive formula:
an = an – 1 + an – 2
where a3 = -5 and a4 = 3


,
,
,
,
,

Answer 1

The first if a twisted version of a Fibonacci sequence :P

If a1=1.2 and a2=2.3 and a(n)=a(n-1)+a(n-2)

a3=3.5, a4=5.8, a5=9.3

So the first five terms are:  1.2, 2.3, 3.5, 5.8, 9.3

The second is another modified Fibonacci sequence...

If a3=-5 and a4=3 then:

3=-5+a2, a2=8

-5=8+a1, a1=-13

a5=-5+3=-2

a6=-2+3=1

So the first six terms are -13, 8, -5, 3, -2, 1