id:A117205 - OEIS Search Results

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Odd squarefree positive integers n such that (n+1)/2 is also squarefree.

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	OFFSET	`1,2`
	COMMENT	`(a(n)+1)/2 = A117206(n)`
	EXAMPLE	`21 and (21+1)/2 = 11 are both squarefree, so 21 is in the sequence.`
	MAPLE	`with(numtheory): a:=proc(n) if n mod 2 =1 and abs(mobius(n))>0 and abs(mobius((n+1)/2))>0 then n else fi end: seq(a(n), n=1..300); - Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 07 2006`
	CROSSREFS	`Cf. A005117, A117203, A117206.` `Sequence in context: A020578 A066587 A047621 this_sequence A136208 A045405 A059311` `Adjacent sequences: A117202 A117203 A117204 this_sequence A117206 A117207 A117208`
	KEYWORD	`nonn`
	AUTHOR	`Leroy Quet (qq-quet(AT)mindspring.com), Mar 02 2006`
	EXTENSIONS	`More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 07 2006`

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Last modified November 18 20:14 EST 2008. Contains 147244 sequences.

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