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A323402
a(n) = 1 if A023900(n) > 0 and A000010(A023900(n)) == A023900(A000010(n)), otherwise a(n) = 0. Here A000010 is Euler totient function phi, and A023900 is its Dirichlet inverse.
1
1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0
OFFSET
1
COMMENTS
Characteristic function of A306146.
For all i, j: A323371(i) = A323371(j) => a(i) = a(j).
PROG
(PARI)
A023900(n) = sumdivmult(n, d, d*moebius(d)); \\ From A023900
A323402(n) = { my(k=A023900(n)); ((k>0)&&(eulerphi(k) == A023900(eulerphi(n)))); };
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 18 2019
STATUS
approved