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A186856
Number of 7-step knight's tours on an (n+2) X (n+2) board summed over all starting positions.
2
16, 1280, 21664, 118480, 372384, 847520, 1584576, 2596480, 3879696, 5424848, 7224912, 9277856, 11583680, 14142384, 16953968, 20018432, 23335776, 26906000, 30729104, 34805088, 39133952, 43715696, 48550320, 53637824, 58978208, 64571472
OFFSET
1,1
LINKS
FORMULA
a(n) = 126440*n^2 - 855176*n + 1332608 for n >= 10. - Andrew Howroyd, Jan 02 2023
EXAMPLE
Some solutions for 5 X 5:
0 1 0 0 0 2 0 0 0 0 0 0 0 1 0 2 0 0 0 0
0 0 0 0 0 0 0 3 0 0 3 6 0 0 0 0 0 1 0 0
0 5 2 0 0 0 1 6 0 0 0 0 2 5 0 0 3 6 0 0
7 0 0 4 0 0 4 0 0 0 0 4 7 0 0 0 0 0 4 7
0 3 6 0 0 0 7 0 5 0 0 0 0 0 0 0 5 0 0 0
PROG
(PARI) row(7, 30) \\ row(m, n) defined in A186851. - Andrew Howroyd, Jan 02 2023
CROSSREFS
Row 7 of A186851.
Sequence in context: A222888 A113104 A227602 * A000490 A308587 A363921
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 27 2011
EXTENSIONS
Terms a(11) and beyond from Andrew Howroyd, Jan 02 2023
STATUS
approved