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A257665
Totient of the n-th perfect number.
0
2, 12, 240, 4032, 16773120, 4294901760, 68719214592, 1152921503533105152, 1329227995784915871750885555673497600, 95780971304118053647396688887409314154826126411694080, 6582018229284824168619876730229320890292528855852623664389292032
OFFSET
1,1
FORMULA
a(n) = A000010(A000396(n)).
MATHEMATICA
Map[EulerPhi, (# (# + 1))/2 & /@ Select[2^Range[100] - 1, PrimeQ]] (* Michael De Vlieger, Jul 25 2015, after Harvey P. Dale at A000396 *)
CROSSREFS
Cf. A000010, A000396, subsequence of A098203.
Sequence in context: A125804 A119700 A141083 * A132877 A007685 A132987
KEYWORD
nonn
AUTHOR
Carl Schildkraut, Jul 12 2015
STATUS
approved