The size of this set is the binomial coefficient (m + n - 1) choose ( n - 1 ).
David On 17 May 2012 14:26, Martin Albrecht <martinralbre...@googlemail.com> wrote: > Hi, > > currently when running e.g. > > sage: IV53 = IntegerVectors(5,3) # length 3 vectors that sum to 5 > sage: IV53.cardinality() > > The algorithm is simply to enumerate all elements (which is the default > algorithm). My question is: is that because that's the best we can do, or > just because nobody sat down and implemented the correct formula (i.e., is it > known)? > > If an exact formula is not know, does anyone know an upper bound (somewhat > tight :))? > > Cheers, > Martin > > -- > name: Martin Albrecht > _pgp: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x8EF0DC99 > _otr: 47F43D1A 5D68C36F 468BAEBA 640E8856 D7951CCF > _www: http://martinralbrecht.wordpress.com/ > _jab: martinralbre...@jabber.ccc.de > > -- > To post to this group, send email to sage-support@googlegroups.com > To unsubscribe from this group, send email to > sage-support+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/sage-support > URL: http://www.sagemath.org -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
