A161788 - OEIS

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A161788

a(n) = the largest integer of the form {2^k -1} that divides n.

1, 1, 3, 1, 1, 3, 7, 1, 3, 1, 1, 3, 1, 7, 15, 1, 1, 3, 1, 1, 7, 1, 1, 3, 1, 1, 3, 7, 1, 15, 31, 1, 3, 1, 7, 3, 1, 1, 3, 1, 1, 7, 1, 1, 15, 1, 1, 3, 7, 1, 3, 1, 1, 3, 1, 7, 3, 1, 1, 15, 1, 31, 63, 1, 1, 3, 1, 1, 3, 7, 1, 3, 1, 1, 15, 1, 7, 3, 1, 1, 3, 1, 1, 7, 1, 1, 3, 1, 1, 15, 7, 1, 31, 1, 1, 3, 1, 7, 3, 1, 1 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,3`
	COMMENTS	`a(n) = 2^A161789(n) - 1. a(A161790(n)) = 1.`
	MAPLE	`A161788 := proc(n) for k from ilog2(n+1) to 0 by -1 do if n mod (2^k-1) = 0 then RETURN(2^k-1); fi; od: end: seq(A161788(n), n=1..120) ; [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jun 27 2009]`
	CROSSREFS	`A000225, A161789, A161790` `Sequence in context: A125127 A058735 A107294 * A170819 A140211 A097706` `Adjacent sequences: A161785 A161786 A161787 * A161789 A161790 A161791`
	KEYWORD	`nonn`
	AUTHOR	`Leroy Quet, Jun 19 2009`
	EXTENSIONS	`Extended by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jun 27 2009`

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Last modified February 17 16:49 EST 2012. Contains 206058 sequences.