A220056 Number of tilings of a 6 X n rectangle using right trominoes and 1 X 1 tiles.

1, 1, 241, 3895, 151817, 4134881, 128938297, 3814023955, 115136505933, 3448441154503, 103598912114381, 3108676107844557, 93324146271938457, 2801146229279170843, 84082823432914559453, 2523871643346500063787, 75758559732310254661669, 2274020749613202850958405

Offset

0,3

Links

Alois P. Heinz, Table of n, a(n) for n = 0..300

Formula

G.f. see Maple program.

Maple

gf:= -(128*x^27 -2784*x^26 +11984*x^25 -8672*x^24 -7128*x^23 -34144*x^22 -125640*x^21 +760596*x^20 -718466*x^19 -174758*x^18 +2760675*x^17 -10918043*x^16 +15110507*x^15 -1068879*x^14 -13774618*x^13 +9742272*x^12 +298116*x^11 -1535703*x^10 -168489*x^9 +78558*x^8 +130467*x^7 +2413*x^6 -18124*x^5 -3982*x^4 +368*x^3 +295*x^2 +12*x -1) /
(3072*x^30 -49664*x^29 -102080*x^28 +441952*x^27 +988592*x^26 -641184*x^25 -6795568*x^24 -3529824*x^23 +39110100*x^22 -11698064*x^21 -93989108*x^20 +89810738*x^19 +53775823*x^18 -80969102*x^17 -68370580*x^16 +104188994*x^15 +46195161*x^14 -118554222*x^13 +26901436*x^12 +45228345*x^11 -25090652*x^10 -4432537*x^9 +5299837*x^8 -37118*x^7 -530937*x^6 +10786*x^5 +29450*x^4 -607*x^3 -523*x^2 -13*x +1):
a:= n-> coeff (series (gf, x, n+1), x, n):
seq(a(n), n=0..30);

Crossrefs

Column k=6 of A220054.

Sequence in context: A167739 A119596 A046948 * A165383 A006687 A060893

Adjacent sequences: A220053 A220054 A220055 * A220057 A220058 A220059

Keyword

nonn

Author

Alois P. Heinz, Dec 03 2012

Status

approved