The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A238550 Number T(n,k) of equivalence classes of ways of placing k 2 X 2 tiles in an n X 6 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=2, 0<=k<=3*floor(n/2), read by rows. 21
 1, 3, 4, 1, 1, 3, 8, 3, 1, 6, 23, 33, 22, 6, 1, 1, 6, 40, 101, 125, 54, 10, 1, 9, 68, 262, 534, 532, 276, 74, 12, 1, 1, 9, 98, 509, 1551, 2505, 2196, 971, 219, 20, 1, 12, 139, 927, 3731, 8772, 12069, 9506, 4366, 1160, 179, 16, 1, 1, 12, 182, 1479, 7644, 24024 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,2 LINKS Andrew Howroyd, Table of n, a(n) for n = 2..953 (terms n=2..69 from Christopher Hunt Gribble) Christopher Hunt Gribble, C++ program EXAMPLE The first 6 rows of T(n,k) are: .\ k  0     1     2     3     4     5     6     7     8     9 n 2     1     3     4     1 3     1     3     8     3 4     1     6    23    33    22     6     1 5     1     6    40   101   125    54    10 6     1     9    68   262   534   532   276    74    12     1 7     1     9    98   509  1551  2505  2196   971   219    20 PROG (C++) See Gribble link. CROSSREFS Cf. A034851, A226048, A102541, A226290, A238009, A228570, A225812, A238189, A238190, A228572, A228022, A231145, A231473, A231568, A232440, A228165, A238551, A238552, A228166, A238555, A238556, A228167, A238557-A238559, A228168, A238581-A238583, A228169, A238586, A238592. Sequence in context: A131107 A046547 A016453 * A275886 A158572 A083532 Adjacent sequences:  A238547 A238548 A238549 * A238551 A238552 A238553 KEYWORD tabf,nonn AUTHOR Christopher Hunt Gribble, Feb 28 2014 EXTENSIONS Terms corrected and xrefs updated by Christopher Hunt Gribble, Apr 26 2015 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified February 25 07:33 EST 2020. Contains 332221 sequences. (Running on oeis4.)