OFFSET
1,1
MATHEMATICA
s = {}; v = EulerPhi @ Range[5]; Do[If[Numerator @ Total[1/v] == 1, AppendTo[s, k - 5]]; v = Join[Rest @ v, {EulerPhi[k]}], {k, 6, 10^7}]; s (* Amiram Eldar, Feb 18 2021 *)
PROG
(PARI) isok(k) = numerator(1/eulerphi(k) + 1/eulerphi(k+1) + 1/eulerphi(k+2) + 1/eulerphi(k+3) + 1/eulerphi(k+4)) == 1;
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Marcus, Feb 18 2021
EXTENSIONS
More terms from Jinyuan Wang, Feb 18 2021
STATUS
approved