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A281528 a(n) = least numerator k such that the proper fraction k/n needs three or more terms as a signed sum of distinct unit fraction, or 0 if no such numerator exists.

%I A281528 #17 Sep 08 2022 08:46:18
%S A281528 0,0,0,0,0,5,0,7,0,7,0,5,10,11,11,5,13,7,13,13,14,5,17,7,10,11,17,8,
%T A281528 19,7,13,13,10,11,23,5,11,11,17,9,25,5,17,13,10,5,29,9,14,11,19,5,22,
%U A281528 13,17,13,11,7,37,7,13,13,19,17,26,5,20,15,22,11,29,5,10
%N A281528 a(n) = least numerator k such that the proper fraction k/n needs three or more terms as a signed sum of distinct unit fraction, or 0 if no such numerator exists.
%H A281528 <a href="/index/Ed#Egypt">Index entries for sequences related to Egyptian fractions</a>
%o A281528 (Magma) lst:=[]; for n in [2..74] do for k in [1..n-1] do f:=k/n; x:=1; v:=0; if Numerator(f) eq 1 then v:=1; else while f lt 2/x do if Numerator(Abs(f-1/x)) eq 1 then v:=1; break; end if; x+:=1; end while; end if; if v eq 0 then Append(~lst, k); break; end if; if k eq n-1 then Append(~lst, 0); end if; end for; end for; lst;
%Y A281528 Cf. A281527.
%K A281528 nonn
%O A281528 2,6
%A A281528 _Arkadiusz Wesolowski_, Jan 23 2017