The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A219971 Number of tilings of a 7 X n rectangle using straight (3 X 1) trominoes and 2 X 2 tiles. 2

%I #7 Dec 07 2012 12:52:27

%S 1,0,3,13,31,170,804,2744,12343,55657,214485,923990,4008013,16241904,

%T 68963484,293830787,1216393406,5135225641,21711233759,90692128053,

%U 381960417890,1609647053073,6749229887672,28396742081001,119506154362773,501879008939056

%N Number of tilings of a 7 X n rectangle using straight (3 X 1) trominoes and 2 X 2 tiles.

%H Alois P. Heinz, <a href="/A219971/b219971.txt">Table of n, a(n) for n = 0..500</a>

%e a(2) = 3, because there are 3 tilings of a 7 X 2 rectangle using straight (3 X 1) trominoes and 2 X 2 tiles:

%e ._._. .___. .___.

%e | | | | | | |

%e | | | |___| |___|

%e |_|_| | | | | |

%e | | | | | |___|

%e |___| |_|_| | | |

%e | | | | | | |

%e |___| |___| |_|_|

%Y Column k=7 of A219967.

%K nonn

%O 0,3

%A _Alois P. Heinz_, Dec 02 2012

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 27 21:52 EDT 2024. Contains 372882 sequences. (Running on oeis4.)