The sum of X recursive positive integers will be divisible by 2 if X is a multiple of __?

Question

There are 5 options for this question:
a) 6
b) 5
c)4
d)3
e)2

I don't quite understand about recursive sequence. I try a few website and I that is it quite hard to understand. Can someone give me a very simple explanation of what is recursive sequence. It is best if you can give me a very simple example.

Please help me with the above question. I don't know how to solve it.

Answer 1

A sequence is recursive if it's general term is given as a function of precedent terms, for example,

a(1) = 1
a(2) = 2
a(n) =a(n-1) + a(n-2) if n > 2

It's kinda confusing, but it seems this problem means the sum of the first x positive integers, (x(x+1))/2. If my guess is right, the right answer is 4.

Answer 2

i think 4
recursive means one after the other
if u take a no x than other no has to be x+1,x+2 .....
so if u take no 1 2 3 4 5 6
only 3 and 4 option remain
now take 2 3 4 5 6 7
so only 4 will remain

Answer 3

I've never heard of recursive integers. Is this explained?

Edit. Oh you mean integers resulting from a recursive relationship.