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A344774
Number of divisors d of n for which A049559(d) = A049559(n), where A049559(n) = gcd(n-1, phi(n)).
2
1, 2, 1, 3, 1, 3, 1, 4, 2, 3, 1, 5, 1, 3, 2, 5, 1, 4, 1, 5, 1, 3, 1, 7, 2, 3, 3, 1, 1, 5, 1, 6, 1, 3, 1, 7, 1, 3, 2, 7, 1, 5, 1, 5, 2, 3, 1, 9, 2, 4, 2, 1, 1, 5, 1, 6, 1, 3, 1, 9, 1, 3, 3, 7, 1, 1, 1, 5, 1, 1, 1, 10, 1, 3, 3, 1, 1, 5, 1, 9, 4, 3, 1, 8, 2, 3, 2, 7, 1, 7, 1, 5, 1, 3, 1, 11, 1, 4, 3, 7, 1, 5, 1, 6, 1
OFFSET
1,2
LINKS
FORMULA
a(n) = Sum_{d|n} [A049559(d) = A049559(n)], where [ ] is the Iverson bracket.
a(n) <= A330747(n).
PROG
(PARI)
A049559(n) = gcd(n-1, eulerphi(n));
A344774(n) = { my(x=A049559(n)); sumdiv(n, d, A049559(d)==x); };
CROSSREFS
Cf. also A344773.
Sequence in context: A084360 A082460 A318573 * A029227 A029214 A134460
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 31 2021
STATUS
approved