A238557 Number T(n,k) of equivalence classes of ways of placing k 2 X 2 tiles in an n X 8 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=2, 0<=k<=4*floor(n/2), read by rows.
1, 4, 9, 6, 1, 1, 4, 18, 22, 6, 1, 8, 49, 139, 204, 145, 54, 8, 1, 1, 8, 83, 392, 1056, 1438, 956, 240, 25, 1, 12, 139, 927, 3731, 8772, 12069, 9506, 4366, 1160, 179, 16, 1, 1, 12, 198, 1742, 9748, 33644, 73274, 98779, 80661, 37886, 9679, 1258, 72
Offset: 2
Examples
The first 4 rows of T(n,k) are: .\ k 0 1 2 3 4 5 6 7 8 n 2 1 4 9 6 1 3 1 4 18 22 6 4 1 8 49 139 204 145 54 8 1 5 1 8 83 392 1056 1438 956 240 25
Links
- Andrew Howroyd, Table of n, a(n) for n = 2..991
- Christopher Hunt Gribble, C++ program
Crossrefs
Formula
tabf,nonn
Extensions
Terms corrected and xrefs updated by Christopher Hunt Gribble, Apr 27 2015