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A161788 a(n) is the largest integer of the form 2^k - 1 that divides n. 3
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; text; internal format)
OFFSET

1,3

COMMENTS

a(n) = 2^A161789(n) - 1.

a(A161790(n)) = 1.

LINKS

Table of n, a(n) for n=1..101.

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) ; # R. J. Mathar, Jun 27 2009

CROSSREFS

Cf. A000225, A161789, A161790.

Sequence in context: A246674 A058735 A107294 * A170819 A140211 A248101

Adjacent sequences:  A161785 A161786 A161787 * A161789 A161790 A161791

KEYWORD

nonn

AUTHOR

Leroy Quet, Jun 19 2009

EXTENSIONS

Extended by R. J. Mathar, Jun 27 2009

STATUS

approved

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Last modified May 9 10:29 EDT 2021. Contains 343732 sequences. (Running on oeis4.)