The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A236584 The number of tilings of a 9 X (2n) floor with 2 X 3 hexominoes. 1
 1, 1, 1, 5, 11, 19, 45, 105, 219, 475, 1061, 2313, 5027, 11035, 24173, 52793, 115499, 252827, 552981, 1209545, 2646419, 5789563, 12664925, 27706873, 60614235, 132602171, 290087749, 634616521, 1388325507, 3037181147 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS Tilings are counted irrespective of internal symmetry: Tilings that match each other after rotations and/or reflections are counted with their multiplicity. LINKS Table of n, a(n) for n=0..29. R. J. Mathar, Paving rectangular regions..., arXiv:1311.6135, Table 52. R. J. Mathar, Tilings of Rectangular Regions by Rectangular Tiles: Counts Derived from Transfer Matrices, arXiv:1406.7788 [math.CO], eq. (35). Index entries for linear recurrences with constant coefficients, signature (2,-1,4,-2). FORMULA G.f.: (1-x)/(-4*x^3+1-2*x+x^2+2*x^4). MAPLE g := (1-x)/(-4*x^3+1-2*x+x^2+2*x^4) ; taylor(%, x=0, 30) ; gfun[seriestolist](%) ; CROSSREFS Cf. A000079 (5Xn floor), A182097 (6Xn floor), A000244 (7Xn floor), A236583 (8X3n floor) Sequence in context: A112794 A163419 A337492 * A072743 A045452 A152085 Adjacent sequences: A236581 A236582 A236583 * A236585 A236586 A236587 KEYWORD easy,nonn AUTHOR R. J. Mathar, Jan 29 2014 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 2 01:46 EDT 2023. Contains 365831 sequences. (Running on oeis4.)