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A295304
a(n) = +1 if sigma(phi(n)) > n, -1 if sigma(phi(n)) < n, and 0 if sigma(phi(n)) = n, where phi = A000010 and sigma = A000203.
3
0, -1, 0, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 0, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, 1, 1, 0, 1, -1, 1, -1, 1, -1, 1, -1, 1, 1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, 1, 1, -1, 1, 1, 1, -1, 1, -1, 1, 1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, 1, 1, 1, 1, -1, 1, -1, 1, 1, 1, -1, 1, 1, 1, 1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, 1, 1
OFFSET
1
LINKS
FORMULA
a(n) = sign(A295302(n)) = sign(sigma(phi(n))-n), where phi = A000010 and sigma = A000203.
PROG
(PARI) A295304(n) = sign(sigma(eulerphi(n)) - n);
CROSSREFS
Cf. A018784 (positions of 0's), A230201 (of -1's), A230203 (of +1's).
Sequence in context: A072165 A358224 A072608 * A171386 A189816 A342000
KEYWORD
sign
AUTHOR
Antti Karttunen, Nov 21 2017
STATUS
approved