A081716 Smallest number x such that phi(x)=A000010(x) has exactly n different decimal digits.

2, 11, 103, 1033, 10247, 102359, 1023487, 10234759, 102345979, 1023475969

Offset

1,1

Links

Table of n, a(n) for n=1..10.

Example

phi applied to the sequence gives: 1, 10, 102, 1032, 10246, 102358, 1023486, 10234758, 102345978, ...

Mathematica

f[x_] := Length[Union[IntegerDigits[x]]]
t=Table[0, {10}];
Do[s=f[n]; If[PrimeQ[n]&&s<11&&t[[s]]==0,
t[[s]]=n], {n, 1, 10000000000}];

Crossrefs

Cf. A007809, A038378, A000010.

Sequence in context: A367852 A285199 A339081 * A334240 A099713 A277461

Adjacent sequences: A081713 A081714 A081715 * A081717 A081718 A081719

Keyword

nonn,fini,full,base

Author

Labos Elemer, Apr 04 2003

Extensions

a(10) from Donovan Johnson, Feb 05 2010

Status

approved