

A186852


Number of 3step knight's tours on an (n+2) X (n+2) board summed over all starting positions.


2



16, 104, 328, 664, 1112, 1672, 2344, 3128, 4024, 5032, 6152, 7384, 8728, 10184, 11752, 13432, 15224, 17128, 19144, 21272, 23512, 25864, 28328, 30904, 33592, 36392, 39304, 42328, 45464, 48712, 52072, 55544, 59128, 62824, 66632, 70552, 74584, 78728, 82984, 87352
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


LINKS



FORMULA

Empirical: a(n) = 56*n^2  56*n  8 for n > 1.


EXAMPLE

Some solutions for 5 X 5:
0 0 0 0 0 3 0 0 0 0 0 0 0 3 0 0 0 3 0 0
0 1 0 0 0 0 0 2 0 0 0 2 0 0 0 0 1 0 0 0
0 0 0 2 0 0 0 0 0 1 0 0 0 0 0 0 0 0 2 0
0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0
0 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0


PROG



CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



