A070835 Numbers n such that phi(reverse(n)) = sigma(n).

1, 168, 1141, 1451, 2139, 2737, 3938, 7597, 11831, 19668, 21415, 23649, 31894, 32383, 40649, 52687, 59677, 121023, 133661, 136831, 146055, 148503, 172095, 190035, 245998, 276058, 302005, 302503, 307705, 396635, 410389, 504557, 516439, 539327, 571577

Offset

1,2

Links

Donovan Johnson, Table of n, a(n) for n = 1..500

Example

phi(reverse(168)) = phi(861) = 480 = sigma(168), so 168 is a term of the sequence.

Mathematica

Select[Range[10^5], EulerPhi[FromDigits[Reverse[IntegerDigits[ # ]]]] == DivisorSigma[1, # ] &]

Crossrefs

Cf. A000203, A000010, A004086, A070856.

Sequence in context: A302887 A235071 A235064 * A112551 A303622 A373213

Adjacent sequences: A070832 A070833 A070834 * A070836 A070837 A070838

Keyword

base,nonn

Author

Joseph L. Pe, May 16 2002

Extensions

More terms from Labos Elemer, Jul 04 2003

Status

approved