Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #14 Jul 14 2019 14:31:42
%S 3,3,5,5,8,5,10,8,11,8,13,8,15,10,13,12,18,11,19,14,19,13,22,14,22,15,
%T 22,18,24,13,25,20,23,18,28,18,25,20,28,22,28,19,29,24,29,20,33,24,35,
%U 23,32,27,33,22,42,28,35,24,38,24,30,26,38,31
%N Number of irreducible Egyptian fractions of denominator n which are the sum of 3 unit fractions.
%H Cyril Banderier, Florian Luca, Francesco Pappalardi, <a href="https://lipn.fr/~cb/Papers/EgyptianFractions.pdf">Numerators of Egyptian fractions</a>, 2019.
%e There are a(2)=3 irreducible fractions with denominator n=2 which are the sums of 3 unit fractions: 1/2 = 1/8 + 1/8 + 1/4 and 3/2 = 1/2 + 1/2 + 1/2, and 5/2 = 1/1 + 1/1 + 1/2.
%Y Cf. A308219, A308220, A308221.
%K nonn
%O 1,1
%A _Cyril Banderier_, May 25 2019