12 Aug
2010
12 Aug
'10
2:16 p.m.
Fred wrote: << I illustrate with the tetranomial case --- the generalisation to any dimension is obvious: \sum_{0<=j<oo} p!q!r!j!/(p+q+r+j)! = p!q!r!/(p+q+r-1)(p+q+r-1)! Does anyone know of a reference for these and similar results . . .
Hmm, dividing both sides, one gets: \sum_(0<=j<oo) j!/(k+j)! = 1/((k-1)(k-1)!) --Dan _____________________________________________________________________ "It don't mean a thing if it ain't got that certain je ne sais quoi." --Peter Schickele