cp's OEIS Frontend

A238583 Number T(n,k) of equivalence classes of ways of placing k 4 X 4 tiles in an n X 9 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=4, 0<=k<=2*floor(n/4), read by rows.

%I A238583 #19 May 29 2017 21:10:17
%S A238583 1,3,2,1,3,4,1,6,9,1,6,14,1,9,32,18,4,1,9,55,65,23,1,12,91,164,87,1,
%T A238583 12,132,320,229,1,15,186,608,648,134,10,1,15,245,1043,1633,770,106,1,
%U A238583 18,317,1736,3659,2800,646,1,18,394,2666,7247,7572,2510
%N A238583 Number T(n,k) of equivalence classes of ways of placing k 4 X 4 tiles in an n X 9 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=4, 0<=k<=2*floor(n/4), read by rows.
%H A238583 Andrew Howroyd, <a href="/A238583/b238583.txt">Table of n, a(n) for n = 4..992</a>
%H A238583 Christopher Hunt Gribble, <a href="/A238009/a238009_1.cpp.txt">C++ program</a>
%e A238583 The first 8 rows of T(n,k) are:
%e A238583 .\ k    0      1      2      3      4
%e A238583 n
%e A238583 4       1      3      2
%e A238583 5       1      3      4
%e A238583 6       1      6      9
%e A238583 7       1      6     14
%e A238583 8       1      9     32     18      4
%e A238583 9       1      9     55     65     23
%e A238583 10      1     12     91    164     87
%e A238583 11      1     12    132    320    229
%o A238583 (C++) See program link.
%Y A238583 Cf. A034851, A226048, A102541, A226290, A238009, A228570, A225812, A238189, A238190, A228572, A228022, A231145, A231473, A231568, A232440, A228165, A238550-A238552, A228166, A238555, A238556, A228167, A238557-A238559, A228168, A238581, A238582, A228169, A238586, A238592
%K A238583 tabf,nonn
%O A238583 4,2
%A A238583 _Christopher Hunt Gribble_, Mar 01 2014
%E A238583 Terms corrected and xrefs updated by _Christopher Hunt Gribble_, Apr 27 2015
%E A238583 Terms a(26) and beyond from _Andrew Howroyd_, May 29 2017