OFFSET
1,2
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..76
FORMULA
MATHEMATICA
Select[Range[10^5], Plus @@ EulerPhi[{#, # + 1}] == # + 1 &] (* Giovanni Resta, May 15 2016 *)
PROG
(PARI) isok(n) = eulerphi(n)+eulerphi(n+1) == n+1; \\ Michel Marcus, May 15 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Feb 07 2002
EXTENSIONS
More terms from Dean Hickerson, Feb 16 2002
STATUS
approved