A104354 - OEIS

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A104354

Euler's totient of A104350(n).

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

Amiram Eldar, Table of n, a(n) for n = 1..640

Reinhard Zumkeller, Products of largest prime factors of numbers <= n.

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];