Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!decvax!harpo!eagle!hou5h!hou5a!hou5d!hogpc!drux3!ihnp4!inuxc!pur-ee!uiucdcs!uiuccsb!leimkuhl From: leimkuhl@uiuccsb.UUCP Newsgroups: net.math Subject: Re: A question on enumerating the ration - (nf) Message-ID: <3627@uiucdcs.UUCP> Date: Wed, 2-Nov-83 20:32:26 EST Article-I.D.: uiucdcs.3627 Posted: Wed Nov 2 20:32:26 1983 Date-Received: Sun, 6-Nov-83 09:35:48 EST Lines: 17 #R:unc:-602900:uiuccsb:9700012:000:544 uiuccsb!leimkuhl Nov 2 19:25:00 1983 >From a friend at Purdue I get the following simple solution to the first problem: Let {an} be an enumeration of the rationals, and let {qn} be such that q1=a1, q2=-a1, q3=a2, q4=-a2,..,q(2n-1)=an, q(2n)=-an,... then the partial sums r1=q1, r2=q1+q2,... are just the sequence (a1,0,a2,0,a3,0,...) which clearly spans the rationals. In this example, neither {qn} nor {rn} is without repitition, and the example here sheds no light on the (probably much more difficult) problem of finding {qn} and {rn} either or both WOR. -Ben Leimkuhler