cp's OEIS Frontend

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.

%I A238550 #24 May 29 2017 21:27:44
%S A238550 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,
%T A238550 532,276,74,12,1,1,9,98,509,1551,2505,2196,971,219,20,1,12,139,927,
%U A238550 3731,8772,12069,9506,4366,1160,179,16,1,1,12,182,1479,7644,24024
%N 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.
%H A238550 Andrew Howroyd, <a href="/A238550/b238550.txt">Table of n, a(n) for n = 2..953</a> (terms n=2..69 from Christopher Hunt Gribble)
%H A238550 Christopher Hunt Gribble, <a href="/A238009/a238009_1.cpp.txt">C++ program</a>
%e A238550 The first 6 rows of T(n,k) are:
%e A238550 .\ k  0     1     2     3     4     5     6     7     8     9
%e A238550 n
%e A238550 2     1     3     4     1
%e A238550 3     1     3     8     3
%e A238550 4     1     6    23    33    22     6     1
%e A238550 5     1     6    40   101   125    54    10
%e A238550 6     1     9    68   262   534   532   276    74    12     1
%e A238550 7     1     9    98   509  1551  2505  2196   971   219    20
%o A238550 (C++) See Gribble link.
%Y A238550 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.
%K A238550 tabf,nonn
%O A238550 2,2
%A A238550 _Christopher Hunt Gribble_, Feb 28 2014
%E A238550 Terms corrected and xrefs updated by _Christopher Hunt Gribble_, Apr 26 2015