|
|
A075475
|
|
Numbers n such that reverse(phi(n+1)) = phi(n).
|
|
1
|
|
|
1, 3, 15, 129, 270, 833, 5044, 59815, 9633693, 26427528, 4642779313, 26594615202, 62935243460, 91770096041, 1648209018135
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
|
|
LINKS
|
|
|
EXAMPLE
|
n=59815: phi(n) = 40992, phi(n+1) = 29904 = rev(phi(n)).
|
|
MATHEMATICA
|
Select[Range[60000], IntegerReverse[EulerPhi[# + 1]] == EulerPhi[#] &] (* Giovanni Resta, Aug 12 2019 *)
|
|
PROG
|
(PARI) isok(n) = eulerphi(n) == fromdigits(Vecrev(digits(eulerphi(n+1)))); \\ Michel Marcus, Aug 12 2019
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base,more
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|