login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A247125 Number of tilings of a 5 X n rectangle using n pentominoes of shapes L, U, X. 7
1, 0, 2, 1, 16, 10, 59, 60, 330, 397, 1520, 2218, 7875, 12820, 39250, 70045, 202168, 384866, 1038051, 2073580, 5385754, 11156701, 28015232, 59580154, 146333795, 317517636, 766142242, 1686735709, 4019319048, 8946988370, 21116854115, 47386013020, 111065223914 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

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

Wikipedia, Pentomino

Index entries for linear recurrences with constant coefficients, signature (0,2,1,12,6,2).

FORMULA

G.f.: -1/(2*x^6+6*x^5+12*x^4+x^3+2*x^2-1).

EXAMPLE

a(4) = 16:

._______.     ._______.     ._______.

| ._____|     | ._____|     | ._| ._|

|_| |_. |     |_| |_. |     | | | | |

|_. ._| |     |_. ._| |     | | | | |

| |_|___|     | |_| | |     |_| |_| |

|_______| (2) |_____|_| (4) |___|___| (4)

._______.     ._______.

| ._____|     | ._____|

|_| ._. |     |_|_. | |

| |_| |_|     | ._| | |

|_____| |     | |___| |

|_______| (2) |___|___| (4) .

MAPLE

a:= n-> (<<0|1|0|0|0|0>, <0|0|1|0|0|0>, <0|0|0|1|0|0>,

          <0|0|0|0|1|0>, <0|0|0|0|0|1>, <2|6|12|1|2|0>>^n)[6, 6]:

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

CROSSREFS

Cf. A174249, A233427, A234312, A247124, A247268.

Sequence in context: A078074 A016447 A095850 * A290315 A113108 A162005

Adjacent sequences:  A247122 A247123 A247124 * A247126 A247127 A247128

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Nov 19 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 | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified February 24 03:49 EST 2018. Contains 299595 sequences. (Running on oeis4.)