All the posible combination of two matrices more than 40 elements

I have two matrix

A=[1]

and

B=[2 3 4]

find the all possible combination of these tow matrices is

the output

C=[1 2; 1 3; 1 4; 1 2 3; 1 2 4; 1 3 4; 1 2 3 4]

I got the answer in form of cell array using following code

C = [];

for j1 = 1:numel(B)

    a = nchoosek(B,j1);

    C = [C;num2cell([repmat(A,size(a,1),1),a],2)];

end

But I have more than 40 elements in the Matrix B.

ncoosek works only 15 elements.

How to find the combinations of more than 40 elements.

[Matt J]

You will need terabytes of memory to hold the result.

Answer 1

[Jan]

Whenever combinations or permutations of a set of more than 10 elements is wanted, it is strongly recommended to calculate the size of the output at first. Usually the problem appears to be too large to be hold at once in the memory.

The limitation of nchoosek to 15 elements has a good reason, so this should let you think twice.