id:A045544 - OEIS Search Results

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Odd values of n for which a regular n-gon can be constructed by compass and straightedge.

+0
15

3, 5, 15, 17, 51, 85, 255, 257, 771, 1285, 3855, 4369, 13107, 21845, 65535, 65537, 196611, 327685, 983055, 1114129, 3342387, 5570645, 16711935, 16843009, 50529027, 84215045, 252645135, 286331153, 858993459, 1431655765, 4294967295 (list; graph; listen)

	OFFSET	`0,1`
	COMMENT	`If there are no more Fermat primes, then 4294967295 is the last term in the sequence.`
	LINKS	`Wilfrid Keller, Prime factors k.2^n + 1 of Fermat numbers F_m`
	FORMULA	`Each term is the product of distinct odd Fermat primes.`
	CROSSREFS	`Cf. A019434. Essentially same as A004729.` `Coincides with A001317 for the first 31 terms only. - Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 22 2001` `Cf. A004729.` `Sequence in context: A094358 A003527 A004729 this_sequence A001317 A053576 A077406` `Adjacent sequences: A045541 A045542 A045543 this_sequence A045545 A045546 A045547`
	KEYWORD	`hard,nonn,nice`
	AUTHOR	`Ken Takusagawa (kenta(AT)cs.stanford.edu)`

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.

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