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A233429
Number of tilings of a 4 X 5n rectangle with 4n pentominoes of any shape.
2
1, 501, 890989, 1666772813, 3125064284901, 5859766228545967, 10987595369808657169, 20602741350971679371521, 38632014757792375332001835, 72438542874037975287077565935, 135828859204452470219311220073385, 254691470323770059993623356733063003
OFFSET
0,2
LINKS
Wikipedia, Pentomino
FORMULA
a(n) ~ c * d^n, where d = 1875.09099182186211660253860201132854810972459605757360689785461004..., c = 0.25279505771792803447854701369537504374767224177480509542292622525... . - Vaclav Kotesovec, Mar 05 2016
CROSSREFS
Quintisection of column k=4 of A233427.
Sequence in context: A097425 A320206 A320215 * A121577 A250609 A251266
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Dec 09 2013
STATUS
approved