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A220772 Number of tilings of a 6 X n rectangle using integer sided rectangular tiles of equal area. 2
1, 4, 21, 54, 343, 1225, 7104, 31777, 169952, 819260, 4234749, 21008157, 107087889, 536982808, 2721665059, 13704483996, 69301052416, 349520578291, 1765820428959, 8911657997748, 45005845549969, 227191526564923, 1147192132487813, 5791672997769659 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

a(n+1)/a(n) tends to r = 5.048917339522305313522214407..., where r is the largest root of 1-5*x+6*x^2-x^3. - Vaclav Kotesovec, Dec 21 2012

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..500

EXAMPLE

a(1) = 4:

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CROSSREFS

Column k=6 of A220777.

Sequence in context: A273780 A033569 A201446 * A242135 A332981 A135559

Adjacent sequences:  A220769 A220770 A220771 * A220773 A220774 A220775

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Dec 19 2012

STATUS

approved

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Last modified June 18 04:41 EDT 2021. Contains 345098 sequences. (Running on oeis4.)