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A250663 Number of tilings of a 12 X n rectangle using 2n hexominoes of shape I. 3

%I

%S 1,1,1,1,1,1,9,19,31,45,61,79,196,419,786,1341,2134,3221,5789,10995,

%T 20621,37149,63931,105379,180201,319826,578034,1040971,1840549,

%U 3171726,5465324,9529019,16830425,29914626,53016504,92934619,161999425,282619059,495436514

%N Number of tilings of a 12 X n rectangle using 2n hexominoes of shape I.

%H Alois P. Heinz, <a href="/A250663/b250663.txt">Table of n, a(n) for n = 0..1000</a>

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Hexomino">Hexomino</a>

%F G.f.: See Maple program.

%p 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

%p -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):

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

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

%Y Column k=6 of A250662.

%Y Cf. A251075.

%K nonn,easy

%O 0,7

%A _Alois P. Heinz_, Nov 26 2014

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Last modified September 24 19:27 EDT 2021. Contains 347651 sequences. (Running on oeis4.)