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A354097
a(n) = 1 if n-phi(n) is a multiple of 4, otherwise 0.
3
1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0
OFFSET
1
FORMULA
a(n) = 1 iff A010873(A051953(n)) == 0.
MATHEMATICA
a[n_] := If[Divisible[n - EulerPhi[n], 4] , 1, 0]; Array[a, 100] (* Amiram Eldar, May 17 2022 *)
PROG
(PARI) A354097(n) = (0==((n-eulerphi(n))%4));
CROSSREFS
Characteristic function of A354098.
Cf. also A354037.
Sequence in context: A353348 A359826 A353350 * A374051 A354927 A173861
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 17 2022
STATUS
approved