A039774 - OEIS

A039774

phi(a(n)) is equal to the product of (the sum of prime factors and the sum of exponents) of (a(n)-1).

3, 5, 9, 25, 31, 57, 116, 144, 154, 288, 372, 414, 624, 792, 10032 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1,1`
	COMMENTS	`Next term if it exists is greater than 100000.`
	LINKS	`Table of n, a(n) for n=1..15.`
	EXAMPLE	`phi(25)=20, 24=2^33^1, (2+3)(3+1)=20.`
	CROSSREFS	`Cf. A000010, A039697.` `Sequence in context: A083366 A006722 A251413 * A114001 A306838 A171879` `Adjacent sequences: A039771 A039772 A039773 * A039775 A039776 A039777`
	KEYWORD	`nonn`
	AUTHOR	`Olivier Gérard`
	STATUS	`approved`

Last modified January 29 00:02 EST 2023. Contains 359905 sequences. (Running on oeis4.)