

A098216


Nonprime numbers n for which cototient[n]=nphi[n] is a decimal repdigit.


3



1, 4, 6, 8, 9, 10, 12, 14, 15, 16, 21, 25, 27, 30, 35, 49, 60, 86, 90, 93, 120, 121, 145, 159, 172, 175, 195, 231, 245, 253, 279, 291, 327, 365, 497, 535, 559, 693, 703, 737, 886, 979, 981, 993, 1037, 1111, 1121, 1411, 1457, 1517, 1617, 1772, 1774, 2047, 2059
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OFFSET

1,2


LINKS



EXAMPLE

n=97002, nphi[n]=66666


MATHEMATICA

ta={{0}}; Do[s=Length[Union[IntegerDigits[nEulerPhi[n]]]]; If[Equal[s, 1]&&!PrimeQ[n], Print[{n, nEulerPhi[n]}]; ta=Append[ta, n]], {n, 1, 100000}]; ta=Delete[ta, 1]; taEulerPhi[ta]


CROSSREFS



KEYWORD

nonn,base


AUTHOR



STATUS

approved



