What is the best way to get the irreducible factors (over Z) of a polynomial as a list?
For example, for x^16-2^16, I would like the output to be
[x - 2, x + 2, x^2 + 4, x^4 + 16, x^8 + 256]
[x - 2 1]
[x + 2 1]
[x^2 + 4 1]
[x^4 + 16 1]
[x^8 + 256 1]
and facs[3,1] will return x^2+4.
ls=[ ]; for(j=1, length(facs), ls=concat(ls, facs[j,1]););
does not work since length(facs)=2
(this seems strange to me - I would have thought length(facs) = 5?)
Maybe there is some simple command in the ? lists that I am missing, but I could not find it.