OFFSET
1,1
FORMULA
a(n) = A179186(n)+2. - R. J. Mathar, Jun 26 2011
MATHEMATICA
Select[Range[3, 5000], EulerPhi[# - 2] == EulerPhi[# + 2] &] (* Alonso del Arte, Jun 28 2011 *)
Flatten[Position[Partition[EulerPhi[Range[5300]], 5, 1], _?(#[[1]] == #[[5]]&), 1, Heads -> False]]+2 (* Harvey P. Dale, Jul 01 2019 *)
PROG
(PARI) for(n=3, 1e4, if(eulerphi(n-2)==eulerphi(n+2), print1(n", "))) \\ Charles R Greathouse IV, Jun 27 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Jun 26 2011
STATUS
approved