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!)
A181946 Number of kites, distinct up to congruence, on an n X n grid (or geoboard). 2

%I #18 Feb 08 2024 16:46:47

%S 0,1,4,11,25,45,81,121,188,261,368,469,641,785,1000,1220,1520,1767,

%T 2161,2471,2961,3396,3946,4403,5164,5744,6517,7227,8201,8936,10122,

%U 10963,12240,13312,14649,15839,17607,18813,20482,21983,24111,25589,27920,29550,31979

%N Number of kites, distinct up to congruence, on an n X n grid (or geoboard).

%C Only convex kites are counted, not concave kites (sometimes called darts or arrowheads).

%H Lucas A. Brown, <a href="https://github.com/lucasaugustus/oeis/blob/main/A181946.py">Python program</a>.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Kite.html">Kite</a>.

%e a(1) = 0 because the 1 X 1 grid has no kites.

%e a(2) = 1 because the 2 X 2 grid has one kite.

%e a(3) = 4 because the 3 X 3 grid has 4 congruence classes of kites, out of 10 kites total:

%e +-------+-------+-------+-------+

%e | . . . | o . o | . . o | . o . |

%e | o o . | . . . | o . . | o . o |

%e | o o . | o . o | o o . | . o . |

%e +-------+-------+-------+-------+

%Y Cf. A181944, A189417.

%K nonn

%O 1,3

%A _Martin Renner_, Apr 03 2012

%E a(7)-a(45) from _Lucas A. Brown_, Feb 08 2024

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 March 28 09:04 EDT 2024. Contains 371240 sequences. (Running on oeis4.)