cp's OEIS Frontend

A186855 Number of 6-step knight's tours on an (n+2) X (n+2) board summed over all starting positions.

%I A186855 #15 Jan 02 2023 21:57:06
%S A186855 16,800,8352,34448,91328,186544,322528,498320,712080,963008,1251104,
%T A186855 1576368,1938800,2338400,2775168,3249104,3760208,4308480,4893920,
%U A186855 5516528,6176304,6873248,7607360,8378640,9187088,10032704,10915488,11835440,12792560,13786848
%N A186855 Number of 6-step knight's tours on an (n+2) X (n+2) board summed over all starting positions.
%H A186855 Andrew Howroyd, <a href="/A186855/b186855.txt">Table of n, a(n) for n = 1..1000</a>
%F A186855 a(n) = 18584*n^2 - 102168*n + 126288 for n > 7.
%e A186855 Some solutions for 5 X 5:
%e A186855   0 0 0 0 6     1 0 0 0 0     0 4 0 0 0     0 0 0 0 0
%e A186855   0 0 5 2 0     0 0 2 0 6     0 0 0 0 6     0 0 0 3 6
%e A186855   0 3 0 0 0     3 0 0 0 0     3 0 5 0 1     0 4 1 0 0
%e A186855   0 0 0 4 1     0 0 0 5 0     0 0 2 0 0     0 0 0 5 2
%e A186855   0 0 0 0 0     0 4 0 0 0     0 0 0 0 0     0 0 0 0 0
%o A186855 (PARI) row(6, 30) \\ row(m,n) defined in A186851. - _Andrew Howroyd_, Jan 02 2023
%Y A186855 Row 6 of A186851.
%K A186855 nonn
%O A186855 1,1
%A A186855 _R. H. Hardin_, Feb 27 2011
%E A186855 Terms a(16) and beyond from _Andrew Howroyd_, Jan 02 2023