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A226371 Number of tilings of a 7 X n rectangle using integer sided square tiles of area > 1. 2
1, 0, 0, 0, 0, 0, 7, 1, 0, 0, 2, 0, 57, 16, 1, 0, 32, 4, 463, 197, 29, 1, 392, 100, 3767, 2150, 518, 46, 4267, 1668, 30763, 21953, 7454, 1128, 43531, 23057, 252755, 215070, 94769, 20728, 426847, 285548, 2094102, 2050219, 1112227, 321677, 4080855, 3290655 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,7

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..1000

FORMULA

G.f.: (-x^12-x^9+2*x^6+x^3-1) / (x^19 -x^18 -x^16 -x^15 -2*x^13 -7*x^12 +x^10 -8*x^9 +x^7 +9*x^6 +x^3-1).

EXAMPLE

a(10) = 2:

._._._._._._._._._._.   ._._._._._._._._._._.

|         |         |   |   |   |   |   |   |

|         |         |   |___|___|___|___|___|

|         |         |   |         |         |

|         |         |   |         |         |

|_________|_________|   |         |         |

|   |   |   |   |   |   |         |         |

|___|___|___|___|___|   |_________|_________|

MAPLE

a:= n-> coeff(series((-x^12-x^9+2*x^6+x^3-1) / (x^19 -x^18 -x^16 -x^15 -2*x^13 -7*x^12 +x^10 -8*x^9 +x^7 +9*x^6 +x^3-1), x, n+1), x, n):

seq(a(n), n=0..70);

CROSSREFS

Column k=7 of A226206.

Sequence in context: A059515 A136428 A271697 * A298937 A223855 A289481

Adjacent sequences:  A226368 A226369 A226370 * A226372 A226373 A226374

KEYWORD

nonn,easy

AUTHOR

Alois P. Heinz, Jun 05 2013

STATUS

approved

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Last modified February 20 20:34 EST 2020. Contains 332084 sequences. (Running on oeis4.)