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Number of ways to express 5/n as Egyptian fractions in just three terms; i.e., 5/n = 1/x + 1/y + 1/z satisfying 1<=x<=y<=z.
6

%I #15 Dec 13 2014 00:50:34

%S 0,1,2,4,3,4,4,7,12,10,3,17,6,21,21,12,6,26,13,28,22,18,9,61,36,18,24,

%T 48,22,57,5,27,38,26,42,60,11,24,56,70,6,71,13,79,79,19,12,99,41,96,

%U 38,55,12,84,62,86,50,41,36,160,6,26,104,57,59,76,16,71,74,136,12,158,22,60,196,52,65,103,25,128,46,30,15,224,73,32,58,141,38,211,71,67,59,41,80,151,24,97,222,292

%N Number of ways to express 5/n as Egyptian fractions in just three terms; i.e., 5/n = 1/x + 1/y + 1/z satisfying 1<=x<=y<=z.

%C See A073101 for the 4/n conjecture due to Erdős and Straus.

%t f[n_] := Length@ Solve[ 5/n == 1/x + 1/y + 1/z && 1 <= x <= y <= z, {x, y, z}, Integers]; Array[f, 70]

%Y Cf. A075248, A004194, A226641, A226642, A192787, A226645, A226646.

%K nonn

%O 1,3

%A _Allan C. Wechsler_ and _Robert G. Wilson v_, Aug 17 2013