On Tue, Mar 27, 2018 at 9:23 AM, Nils Bruin <nbr...@sfu.ca> wrote: > On Tuesday, March 27, 2018 at 12:07:41 AM UTC-7, Ralf Stephan wrote: >> >> Hello, >> I thought I'd try Sage for a casual computation. I was interested in which >> numbers of the form (2^n - (-1)^n)/3 are prime. I first tried out n=23: >> >> sage: (2^23+1)/3 >> 2796203 >> sage: _.is_prime() >> False >> sage: factor(2796203) >> 2796203 >> > Just as a data point: my magma initialization file contains: > > intrinsic Factorisation(n::FldRatElt) -> SeqEnum > L,u:=Factorisation(Numerator(n)); > L:= L cat [ <u[1],-u[2]> : u in Factorisation(Denominator(n))]; > return L,u; > end intrinsic;
Just curious -- does that have the *potential* to break Magma library code? E.g., maybe deep in some package code I wrote 20 years ago for Magma, I use Factorization on a reational, and assume that the output is "trivial". (I'm pretty sure I didn't, but...) -- William (http://wstein.org) -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
