Fibonacci sequence, slightly different.

I am trying to write a code for the fibonacci sequence, but instead of adding the the term to its previous one, I want a number to start with (say 4, my code input called begin) and its first two outputs would be 4. It would loop n times (say 7 for this example). The output would look like [4 4 8 12 16 20 24]. How could I generalize this. So far I have

if begin ~=1 || begin ~= 0
    seq(1)=begin;
    seq(2)=begin;
    k=3;
    while k <= n
        seq(k)=seq(begin-1)+begin;
        k =k+1;
    end
end

Answer 1

[James Tursa]

Looks like your indexing into seq is not quite right. Try this:

        seq(k)=seq(k-1)+begin;

[Bob Whiley]

Perfect, thanks!

Answer 2

[Titus Edelhofer]

Hi,

I don't see what this has to do with Fibonacci though ;-). But you don't need the loop, just do something like

seq = begin * [1 1:(n-1)];

Titus

Answer 3

[Evan]

It seems to be quite close. You just need to make one small change. You should reference the seq variable using the index, k, not the begin variable:

begin = 4;
n = 5;
if begin ~=1 && begin ~= 0

      seq(1)=begin;
      seq(2)=begin;
      k=3;

      while k <= n
          seq(k)=seq(k-1)+seq(k-2);

          k = k+1;
      end

end

Note that your example output isn't a fibonnaci sequence. Is this really what you want? If so, you could just make that array with:

begin = 4;
n = 5;
seq = [begin begin:begin:begin * n];

Answer 4

[Bob Whiley]

If he beginning number were 0, how could I make it so the first index in the output vector is 0, then the sequence continues normally after. Like if n = 6, and begin = 0, how could I get the output [0 1 1 2 3 5]

What I have so far is

if begin == 0

seq(1)=1;

seq(2)=1;

k=3;

while k <= n

seq(k)=seq(k-1)+seq(k-2);

k=k+1;

end

end