Array indexing nth spaced element

How do I extract the nth spaced elements of an array?

a = [1 2 3 4 5 6 7 8 9 10 11 12]

I want to extract a(1), a(1+n), a(1+2n),... elements.

My array is quite long, so writing the above manually is not an option.

Is there a way of doing so without using a for loop?

Answer 1

[Adam]

a( 1:n:end )