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A053568
Totients of nontotient numbers.
1
2, 4, 6, 6, 10, 12, 6, 8, 16, 18, 12, 22, 20, 12, 18, 28, 30, 20, 16, 24, 36, 18, 24, 40, 42, 24, 46, 42, 20, 32, 52, 40, 36, 58, 60, 30, 36, 48, 66, 32, 44, 70, 72, 36, 40, 36, 60, 78, 54, 82, 64, 42, 56, 88, 24, 72, 60, 46, 72, 96, 42, 60, 100, 102, 48, 106
OFFSET
1,1
COMMENTS
See comment at analogous sequence A053474.
LINKS
FORMULA
a(n) = A000010(A007617(n)).
EXAMPLE
If k = 19 then there is no number x such that phi(x) = k exists; however, phi(19) = 18.
k = 27 is also a nontotient number whose totient is 18.
PROG
(PARI) lista(nn) = for (n=1, nn, if (!istotient(n), print1(eulerphi(n), ", "))); \\ Michel Marcus, Nov 20 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Jan 17 2000
STATUS
approved