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A238559
Number T(n,k) of equivalence classes of ways of placing k 4 X 4 tiles in an n X 8 rectangle under all symmetry operations of the rectangle; irregular triangle T(n,k), n>=4, 0<=k<=2*floor(n/4), read by rows.
21
1, 3, 1, 1, 3, 2, 1, 6, 4, 1, 6, 6, 1, 9, 17, 5, 1, 1, 9, 32, 18, 4, 1, 12, 56, 46, 13, 1, 12, 84, 90, 31, 1, 15, 121, 193, 98, 13, 1, 1, 15, 162, 360, 275, 66, 6, 1, 18, 212, 664, 672, 250, 31, 1, 18, 266, 1080, 1408, 672, 110, 1, 21, 329, 1711, 2797, 1772, 432, 23, 1
OFFSET
4,2
LINKS
Christopher Hunt Gribble, C++ program
EXAMPLE
The first 11 rows of T(n,k) are:
.\ k 0 1 2 3 4 5 6
n
4 1 3 1
5 1 3 2
6 1 6 4
7 1 6 6
8 1 9 17 5 1
9 1 9 32 18 4
10 1 12 56 46 13
11 1 12 84 90 31
12 1 15 121 193 98 13 1
13 1 15 162 360 275 66 6
14 1 18 212 664 672 250 31
PROG
(C++) See Gribble link.
KEYWORD
tabf,nonn
AUTHOR
EXTENSIONS
Terms corrected and xrefs updated by Christopher Hunt Gribble, Apr 27 2015
Terms a(31) and beyond from Andrew Howroyd, May 29 2017
STATUS
approved