A270063 Number of tilings of a 3 X n rectangle using monominoes and trominoes of any shape.

1, 2, 14, 93, 590, 3710, 23509, 148796, 940916, 5952243, 37655502, 238204978, 1506870209, 9532433288, 60301864000, 381467462217, 2413150656124, 15265511608858, 96569119066667, 610893045560410, 3864489168524208, 24446630393071735, 154648573589573678

Offset

0,2

Links

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

Formula

G.f.: -(x^15 +2*x^14 +5*x^13 -4*x^12 -7*x^11 -21*x^10 +12*x^9 +11*x^8 +24*x^7 -21*x^6 -13*x^5 +16*x^3 +2*x^2 +2*x -1) / (x^18 +2*x^17 +5*x^16 -9*x^15 -21*x^14 -54*x^13 +32*x^12 +46*x^11 +147*x^10 +21*x^9 -40*x^8 -110*x^7 -17*x^6 -11*x^5 -32*x^4 -37*x^3 -8*x^2 -4*x +1).

Crossrefs

Column k=3 of A270061.

Cf. A134438.

Sequence in context: A341395 A072148 A297474 * A033169 A090410 A066052

Adjacent sequences: A270060 A270061 A270062 * A270064 A270065 A270066

Keyword

nonn,easy

Author

Alois P. Heinz, Mar 09 2016

Status

approved