Matrix for two variables

I have 2 variables, a and b with respective values 1.123456789 and 3.123456789. Please help me to generate the matrix for the possible combination based on the formula 2^n, n = integer number 1 to 50. E.g if n=3, the output should be a matrix of 8 by 3:

1.123456789  1.123456789   1.123456789
1.123456789   1.123456789   3.123456789
1.123456789   3.123456789  1.123456789
1.123456789   3.123456789  3.123456789
3.123456789  1.123456789   1.123456789
3.123456789  1.123456789   3.123456789
3.123456789  3.123456789  1.123456789
3.123456789  3.123456789  3.123456789

[Azzi Abdelmalek]

what is the link between a, b and 2^n. Combinaison of what?

Answer 1

[Andrei Bobrov]

use function ff2n from Statistics Toolbox

n = 3;
a = [1.123456789 , 3.123456789];
ii = ff2n(n)+1;
out = a(ii);

[Enfa White]

The a and b values generated by ff2n is a matrix of 8 by 3 (for n=3). How can I use these a and b as the input values for the following function:

function my_func = out(~,~)

x = (1+sin(5*a)-(1/sqrt(8*(sin(a))))) y = (1+sin(5*b)+(1/sqrt(8*(sin(b)))))

out=(2*(x+y))/2+x