A011948 - OEIS

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A011948

Number of Barlow packings with group P63mc that repeat after 2n layers.

1, 1, 4, 7, 18, 31, 70, 126, 261, 484, 960, 1800, 3514, 6643, 12852, 24457, 47151, 90157, 173740, 333498 (list; graph; refs; listen; history; internal format)

	OFFSET	`6,3`
	REFERENCES	`T. J. McLarnan, The numbers of polytypes ..., Zeits. Krist. 155, 269-291 (1981).`
	CROSSREFS	`Cf. A045668.` `Sequence in context: A005509 A147366 A056318 * A146387 A124400 A077920` `Adjacent sequences: A011945 A011946 A011947 * A011949 A011950 A011951`
	KEYWORD	`nonn,easy`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com).`

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Last modified February 17 06:27 EST 2012. Contains 205998 sequences.