# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a081716 Showing 1-1 of 1 %I A081716 #11 Oct 15 2013 22:31:52 %S A081716 2,11,103,1033,10247,102359,1023487,10234759,102345979,1023475969 %N A081716 Smallest number x such that phi(x)=A000010(x) has exactly n different decimal digits. %e A081716 phi applied to the sequence gives: 1, 10, 102, 1032, 10246, 102358, 1023486, 10234758, 102345978, ... %t A081716 f[x_] := Length[Union[IntegerDigits[x]]] %t A081716 t=Table[0, {10}]; %t A081716 Do[s=f[n]; If[PrimeQ[n]&&s<11&&t[[s]]==0, %t A081716 t[[s]]=n], {n, 1, 10000000000}]; %Y A081716 Cf. A007809, A038378, A000010. %K A081716 nonn,fini,full,base %O A081716 1,1 %A A081716 _Labos Elemer_, Apr 04 2003 %E A081716 a(10) from _Donovan Johnson_, Feb 05 2010 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE