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A104354 Euler's totient of A104350(n). 1
1, 1, 2, 4, 16, 48, 288, 576, 1728, 8640, 86400, 259200, 3110400, 21772800, 108864000, 217728000, 3483648000, 10450944000, 188116992000, 940584960000, 6584094720000, 72425041920000, 1593350922240000, 4780052766720000, 23900263833600000, 310703429836800000 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
LINKS
FORMULA
a(n) = A000010(A104350(n)).
MATHEMATICA
EulerPhi[FoldList[Times, Array[FactorInteger[#][[-1, 1]] &, 30]]] (* Amiram Eldar, Apr 08 2024 *)
PROG
(PARI) gpf(n) = my(f=factor(n)[, 1]); f[#f];
a(n) = eulerphi(prod(i=2, n, gpf(i))); \\ Michel Marcus, Nov 12 2023
CROSSREFS
Sequence in context: A248748 A350646 A165905 * A153948 A284730 A255730
KEYWORD
nonn,changed
AUTHOR
Reinhard Zumkeller, Mar 06 2005
EXTENSIONS
a(1) prepended by Michel Marcus, Nov 12 2023
STATUS
approved

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Last modified April 13 05:19 EDT 2024. Contains 371639 sequences. (Running on oeis4.)