id:A136623 - OEIS Search Results

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a(n) = largest prime power that is <=n and is coprime to n.

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	OFFSET	`1,3`
	COMMENT	`a(n) = A031218(n-1) for all n where 2 <= n <= 33.`
	LINKS	`Leroy Quet, Home Page (listed in lieu of email address)`
	EXAMPLE	`The largest prime power that is <= 34 is 32 = 2^5. But 32 is not coprime to 34. The next smaller prime power is 31 = 31^1. 31 is indeed coprime to 34; so a(34) = 31.`
	PROGRAM	`(PARI) a(n) = {x=n; while((matsize(factor(x))[1]>1) \| (gcd(x, n)!=1), x--); x} [From Michael Porter (michael_b_porter(AT)yahoo.com), Oct 07 2009]`
	CROSSREFS	`Cf. A031218.` `Sequence in context: A162683 A073137 A131233 this_sequence A031218 A163382 A094017` `Adjacent sequences: A136620 A136621 A136622 this_sequence A136624 A136625 A136626`
	KEYWORD	`more,nonn`
	AUTHOR	`Leroy Quet Apr 14 2008`
	EXTENSIONS	`More terms from Michael Porter (michael_b_porter(AT)yahoo.com), Oct 07 2009`

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Last modified December 4 23:11 EST 2009. Contains 170347 sequences.

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