A067583 - OEIS

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A067583

Integers of the form phi(n^n)/phi(n)^n where phi is the Euler totient function A000010(n).

1, 2, 8, 243, 128, 177147, 32768, 129140163, 94143178827, 2147483648, 50031545098999707, 26588814358957503287787, 19383245667680019896796723, 9223372036854775808, 7509466514979724803946715958257547 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1,2`
	LINKS	`Table of n, a(n) for n=1..15.`
	FORMULA	`If A007694(n)==0 (mod 3) (or equivalently if A007694(n) = 2^u*3^v with u, v >=1) then a(n) =3^(A007694(n) -1); if A007694(n)=2^u a(n)=2^(A007694(n) -1). Remark : if n=3^v phi(n^n)/phi(n)^n=1/2^(n-1)`
	MATHEMATICA	`Select[Table[EulerPhi[n^n]/EulerPhi[n]^n, {n, 100}], IntegerQ] (* Harvey P. Dale, Dec 19 2021 *)`
	CROSSREFS	`Sequence in context: A338543 A125264 A028985 * A120378 A012345 A012341` `Adjacent sequences: A067580 A067581 A067582 * A067584 A067585 A067586`
	KEYWORD	`nonn`
	AUTHOR	`Benoit Cloitre, Jan 30 2002`
	STATUS	`approved`

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Last modified February 3 07:33 EST 2023. Contains 360024 sequences. (Running on oeis4.)