OFFSET
1,1
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..10000
EXAMPLE
1/phi(2283)+1/phi(2284)+1/phi(2285) = 1/1520+1/1140+1/1824 = 1/480 so 2283 is in the sequence.
MATHEMATICA
Select[Range[10000], IntegerQ[1/Sum[1/EulerPhi[ #+i], {i, 0, 2}]]&]
PROG
(PARI) isok(k) = numerator(1/eulerphi(k) + 1/eulerphi(k+1) + 1/eulerphi(k+2)) == 1; \\ Michel Marcus, Feb 18 2021
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Aug 27 2002
EXTENSIONS
Edited by Dean Hickerson, Sep 03 2002
STATUS
approved