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A108550 Number of ways of packing a 3 X (2n-1) rectangle with dominoes, leaving one space unoccupied. 0
2, 18, 160, 1530, 14800, 143386, 1389432, 13464130, 130472968, 1264337250, 12251953552, 118726523722, 1150509376512, 11148914193898, 108037613809384, 1046929395512082, 10145181113692600, 98311022950389682 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..18.

FORMULA

G.f.: ( (2x)(1+x-x^2)(1-4x+x^2))/((1-10x+3x^2)(1-x)^2))

CROSSREFS

Cf. A001835.

Sequence in context: A052838 A052876 A121933 * A322282 A270369 A144513

Adjacent sequences:  A108547 A108548 A108549 * A108551 A108552 A108553

KEYWORD

easy,nonn

AUTHOR

Frans Clauwens (F.Clauwens(AT)science.ru.nl), Jun 09 2005

STATUS

approved

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Last modified September 18 23:30 EDT 2020. Contains 337175 sequences. (Running on oeis4.)