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

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

Offset: 0

Author

Alois P. Heinz, Nov 26 2014

Keywords

• nonn
• easy

Links

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

Crossrefs

Column k=6 of A250662.

Cf. A251075.

Programs

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);

Formula

G.f.: See Maple program.