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.
%I A073764 #8 Oct 15 2013 22:31:28
%S A073764 6,0,10,15,14,21,18,35,22,33,26,39,0,65,30,36,38,57,44,95,46,63,42,
%T A073764 115,50,64,58,87,54,75,68,155,60,99,74,111,72,185,66,117,86,129,92,
%U A073764 215,94,141,78,235,84,105,98,100,96,265,90,135,118,147,122,183,108,305,102
%N A073764 a(n) = least number x such that A045763(x)=n or 0 if no such number exists.
%C A073764 A070297 without its term a(0). [From _R. J. Mathar_, Sep 23 2008]
%e A073764 A045763(x)=5 first holds if x=14 because unrelated set of 14={4,6,8,10,12} has 5 entries. No solutions were found for n=2,13,67,93 when tested at <100000.
%t A073764 t=Table[0, {100}]; Do[s=n+1-DivisorSigma[0, n]-EulerPhi[n]; If[s<101&&t[[s]]==0, t[[s]]=n], {n, 1, 100000}]; t
%Y A073764 Cf. A045763, A073757-A073766.
%K A073764 nonn
%O A073764 1,1
%A A073764 _Labos Elemer_, Aug 08 2002