A069969 Numbers n such that phi(reverse(n)) = phi(reverse(n-1)) + phi(reverse(n-2)).

3, 5, 7, 34, 42, 83, 223, 342, 443, 464, 522, 563, 584, 653, 2194, 2554, 3623, 5704, 6904, 8084, 8134, 8254, 14455, 24653, 29393, 48023, 50882, 52834, 56663, 58483, 58814, 65893, 66784, 82315, 83324, 91373, 98254

Offset

1,1

Links

Table of n, a(n) for n=1..37.

Example

phi(reverse(223)) = phi(322) = 132 = 72 + 60 = phi(222) + phi(122) = phi(reverse(223-1)) + phi(reverse(223-2)).

Mathematica

rev[n_] := FromDigits[Reverse[IntegerDigits[n]]]; Select[Range[3, 10^5], EulerPhi[rev[ # ]] == EulerPhi[rev[ # - 1]] + EulerPhi[rev[ # - 2]] &]

Crossrefs

Sequence in context: A095714 A137864 A256154 * A067232 A327413 A106115

Adjacent sequences: A069966 A069967 A069968 * A069970 A069971 A069972

Keyword

base,nonn

Author

Joseph L. Pe, Apr 29 2002

Status

approved