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A193454 Sum of odd divisors of phi(n). 3
1, 1, 1, 1, 1, 1, 4, 1, 4, 1, 6, 1, 4, 4, 1, 1, 1, 4, 13, 1, 4, 6, 12, 1, 6, 4, 13, 4, 8, 1, 24, 1, 6, 1, 4, 4, 13, 13, 4, 1, 6, 4, 32, 6, 4, 12, 24, 1, 32, 6, 1, 4, 14, 13, 6, 4, 13, 8, 30, 1, 24, 24, 13, 1, 4, 6, 48, 1, 12, 4, 48, 4, 13, 13, 6, 13, 24, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,7
COMMENTS
Phi(n): A000010 is the Euler totient function. This sequence equals A193254(n) for n < 63.
LINKS
FORMULA
a(n) = A000593(A000010(n)). - Michel Marcus, Jan 14 2014
EXAMPLE
a(63) = 13 because phi(63) = 36, and the sum of the 3 odd divisors {1, 3, 9} is 13.
MATHEMATICA
Table[Total[Select[Divisors[EulerPhi[n]], OddQ[ # ]&]], {n, 58}]
PROG
(PARI) a(n) = sumdiv(eulerphi(n), d, (d%2)*d); \\ Michel Marcus, Jan 14 2014
CROSSREFS
Sequence in context: A257231 A196757 A193254 * A368921 A322819 A089655
KEYWORD
nonn
AUTHOR
Michel Lagneau, Jul 26 2011
STATUS
approved

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Last modified July 17 08:16 EDT 2024. Contains 374360 sequences. (Running on oeis4.)