OFFSET
1
LINKS
FORMULA
a(n) = 1 if n < A062401(n), 0 otherwise.
MATHEMATICA
Array[Boole[# < EulerPhi@ DivisorSigma[1, #]] &, 120] (* Michael De Vlieger, Nov 22 2017 *)
PROG
(PARI) a(n) = n < eulerphi(sigma(n)); \\ Michel Marcus, Nov 23 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 22 2017
STATUS
approved