A057420 - OEIS

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A057420

Axially symmetric n-celled polyominoes with 1 hole.

1, 3, 8, 25, 45, 137, 221, 650, 1006, 2857, 4370, 12050, 18417, 49516, 76037, 200184, 309411, 800440, 1245934, 3176482 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`9,2`
	LINKS	`Table of n, a(n) for n=9..28.` `Tomás Oliveira e Silva, Enumeration of polyominoes`
	CROSSREFS	`Sequence in context: A328272 A220486 A180380 * A076049 A026970 A026980` `Adjacent sequences: A057417 A057418 A057419 * A057421 A057422 A057423`
	KEYWORD	`nonn`
	AUTHOR	`N. J. A. Sloane, Sep 05 2000`
	STATUS	`approved`

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Last modified April 17 05:36 EDT 2021. Contains 343059 sequences. (Running on oeis4.)