I keep getting the error( this is in Matlab) Attempted to access r(0,0); index must be a positive integer or logical.

Error in ==> Romberg at 15

I ran it with Romberg(1.3, 2.19,8)

I think the problem is the statment is not logical because I made it positive and still got the same error. anyone got some ideas of what i could do?

function Romberg(a, b, n)

h = b - a;

r = zeros(n,n);

for i = 1:n

h = h/2;

sum1 = 0;

for k = 1:2:2^(i)

    sum1 = sum1 + f(a + k*h);

end

r(i,0) = (1/2)*r(i-1,0) + (sum1)*h;

for j = 1:i

    r(i,j) = r(i,j-1) + (r(i,j-1) - r(i-1,j-1))/((4^j) - 1);

end

end

disp(r);

end

function f_of_x = f(x)

f_of_x = sin(x)/x;

end