A073764 - OEIS

%I #8 Oct 15 2013 22:31:28

%S 6,0,10,15,14,21,18,35,22,33,26,39,0,65,30,36,38,57,44,95,46,63,42,

%T 115,50,64,58,87,54,75,68,155,60,99,74,111,72,185,66,117,86,129,92,

%U 215,94,141,78,235,84,105,98,100,96,265,90,135,118,147,122,183,108,305,102

%N a(n) = least number x such that A045763(x)=n or 0 if no such number exists.

%C A070297 without its term a(0). [From _R. J. Mathar_, Sep 23 2008]

%e 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 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 Cf. A045763, A073757-A073766.

%K nonn

%O 1,1

%A _Labos Elemer_, Aug 08 2002