A104363 - OEIS

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A104363

Euler's totient of A104357(n) = A104350(n) - 1.

1, 4, 10, 58, 178, 1258, 2280, 7558, 37798, 415798, 1229760, 16144536, 113488440, 567495336, 1135133998, 19295619336, 56915913600, 1085995965600, 5499724229998, 37888326510336, 423202615117920, 9425816095466520, 29220034833989998, 146100157813443360, 1882777893068160000, 5683471349506454400, 39885027849235856880

(list; graph; refs; listen; history; text; internal format)

OFFSET

2,2

LINKS

Max Alekseyev, Table of n, a(n) for n = 2..145 (terms for n = 2..74 from Amiram Eldar)

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

FORMULA

a(n) = A000010(A104357(n)).

MATHEMATICA

a[n_] := EulerPhi[-1 + Product[FactorInteger[k][[-1, 1]], {k, 1, n}]]; Array[a, 50, 2] (* Amiram Eldar, Feb 12 2020 *)

CROSSREFS

Cf. A000010, A104357, A104358, A104359, A104360, A104361, A104362, A104364, A104371.