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%I #6 Dec 10 2020 16:47:12
%S 0,1,0,0,0,0,0,0,0,0,0,6,0,0,0,0,0,0,0,0,0,0,0,0,24,0,0,0,0,0,24,24,
%T 24,0,0,0,0,24,120,0,0,0,0,120,0,240,0,0,0,0,840,0,720,120,24,120,0,
%U 1440,0,720,720,120,840,0,2280,720,960,1080,0,840,0,11760,0,5040,1440,720
%N Number of compositions (ordered partitions) of n into distinct parts such that the sum of reciprocals of parts is 1.
%C Also the number of ordered ways to express 1 as the sum of distinct unit fractions such that the sum of the denominators is n.
%H <a href="/index/Com#comp">Index entries for sequences related to compositions</a>
%H <a href="/index/Ed#Egypt">Index entries for sequences related to Egyptian fractions</a>
%e a(11) = 6 because we have 2 + 3 + 6 = 2 + 6 + 3 = 3 + 2 + 6 = 3 + 6 + 2 = 6 + 2 + 3 = 6 + 3 + 2 = 11 and 1/2 + 1/3 + 1/6 = 1.
%Y Cf. A051907, A051908, A058360, A339627, A339628.
%K nonn
%O 0,12
%A _Ilya Gutkovskiy_, Dec 10 2020