A209337 - OEIS

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A209337

Number of n-bead necklaces labeled with numbers -1..1 allowing reversal, with sum zero with no three beads in a row equal.

1, 2, 1, 4, 5, 14, 21, 51, 102, 249, 555, 1358, 3201, 7890, 19232, 47869, 118955, 298875, 752039, 1904621, 4835666, 12330144, 31521037, 80836979, 207803455, 535535393, 1383064966, 3579351724, 9280561947 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1,2`
	COMMENTS	`Column 1 of A209344.`
	LINKS	`Table of n, a(n) for n=1..29.`
	EXAMPLE	`Some solutions for n=10:` `.-1...-1...-1...-1...-1...-1...-1...-1...-1...-1...-1...-1...-1...-1...-1...-1` `..0....0...-1....0...-1....0....0....0....0...-1....0....0....0....0....0....0` `.-1....0....0....0....0....0....0...-1...-1....0...-1....0....0...-1....1...-1` `..0...-1....0....1...-1...-1...-1....0....0...-1....1...-1....1....1....0....0` `..0....0...-1....0....1....0....1....1....1....1....1....0...-1...-1...-1....0` `..1....1....0...-1....0....0...-1...-1...-1....1...-1....1....1....1....1....1` `..1....0....1....1....1....1....1....1....1...-1....0...-1....0....0...-1....0` `..0....1....0...-1....0....0....0....0...-1....1...-1....0....0....1....1....1` `.-1...-1....1....1....1....0....0....0....1....0....1....1...-1...-1...-1....0` `..1....1....1....0....0....1....1....1....1....1....1....1....1....1....1....0`
	CROSSREFS	`Sequence in context: A350087 A091232 A336398 * A243004 A137424 A083007` `Adjacent sequences: A209334 A209335 A209336 * A209338 A209339 A209340`
	KEYWORD	`nonn`
	AUTHOR	`R. H. Hardin, Mar 06 2012`
	STATUS	`approved`

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Last modified May 14 09:19 EDT 2024. Contains 372532 sequences. (Running on oeis4.)