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A250663 Number of tilings of a 12 X n rectangle using 2n hexominoes of shape I. 3
1, 1, 1, 1, 1, 1, 9, 19, 31, 45, 61, 79, 196, 419, 786, 1341, 2134, 3221, 5789, 10995, 20621, 37149, 63931, 105379, 180201, 319826, 578034, 1040971, 1840549, 3171726, 5465324, 9529019, 16830425, 29914626, 53016504, 92934619, 161999425, 282619059, 495436514 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,7

LINKS

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

Wikipedia, Hexomino

FORMULA

G.f.: See Maple program.

MAPLE

gf:= -(x^15-x^12-2*x^10-2*x^9+x^7+2*x^6+x^5+x^4+x^3-1) *(x-1)^5 *(x+1)^5 *(x^2+x+1)^5 *(x^2-x+1)^5 / (x^51 -x^48 -3*x^46 -8*x^45 +2*x^43 +8*x^42 +3*x^41 +18*x^40 +28*x^39 -x^38 -11*x^37 -29*x^36 -15*x^35 -45*x^34

-56*x^33 +5*x^32 +24*x^31 +61*x^30 +30*x^29 +60*x^28 +70*x^27 -10*x^26 -25*x^25 -80*x^24 -30*x^23 -45*x^22 -61*x^21 +10*x^20 +10*x^19 +71*x^18 +15*x^17 +28*x^16 +38*x^15 -5*x^14 -2*x^13 -43*x^12 -8*x^11 -8*x^10 -13*x^9 +x^8 -4*x^7 +14*x^6 +x^3 +x -1):

a:= n-> coeff(series(gf, x, n+1), x, n):

seq(a(n), n=0..40);

CROSSREFS

Column k=6 of A250662.

Cf. A251075.

Sequence in context: A056126 A190513 A190576 * A274590 A051811 A034056

Adjacent sequences:  A250660 A250661 A250662 * A250664 A250665 A250666

KEYWORD

nonn,easy

AUTHOR

Alois P. Heinz, Nov 26 2014

STATUS

approved

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Last modified July 23 22:13 EDT 2021. Contains 346265 sequences. (Running on oeis4.)