cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A201648 The fourth of the five known sets of nine distinct odd numbers the sum of whose reciprocals is 1.

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%I A201648 #9 Feb 04 2016 16:15:29
%S A201648 3,5,7,9,11,15,21,231,315
%N A201648 The fourth of the five known sets of nine distinct odd numbers the sum of whose reciprocals is 1.
%C A201648 John Leech showed that nine is the smallest number of odd numbers with this property.
%C A201648 This set was apparently discovered by S. Yamashita in 1976.
%D A201648 R. K. Guy, Unsolved Problems in Number Theory (UPINT), Section D11.
%H A201648 Nechemia Burshtein, <a href="http://dx.doi.org/10.1016/j.jnt.2007.01.007">The equation sum(i=1,9,1/xi)=1 in distinct odd integers has only the five known solutions</a>, Journal of Number Theory, Volume 127, Issue 1, November 2007, Pages 136-144.
%H A201648 The Prime Puzzles and Problems Connection, <a href="http://www.primepuzzles.net/problems/prob_035.htm">Problem 35</a>
%H A201648 <a href="/index/Ed#Egypt">Index entries for sequences related to Egyptian fractions</a>
%Y A201648 There are five known sets of nine odd numbers with this property: A201644, A201646, A201647, A201648, A201649.
%K A201648 nonn,fini,full
%O A201648 1,1
%A A201648 _N. J. A. Sloane_, Dec 03 2011