cp's OEIS Frontend

A187593 Number of 10-step E, S, NW and NE-moving king's tours on an n X n board summed over all starting positions.

%I A187593 #8 Jul 22 2025 10:49:16
%S A187593 0,0,0,3108,45960,219432,609070,1243461,2111652,3201436,4508924,
%T A187593 6034116,7777012,9737612,11915916,14311924,16925636,19757052,22806172,
%U A187593 26072996,29557524,33259756,37179692,41317332,45672676,50245724,55036476,60044932
%N A187593 Number of 10-step E, S, NW and NE-moving king's tours on an n X n board summed over all starting positions.
%C A187593 Row 10 of A187586
%F A187593 Empirical: a(n) = 108852*n^2 - 978404*n + 2100276 for n>8
%e A187593 Some solutions for 4X4
%e A187593 ..0..8..9.10....0..7..8..9....0..0..0..2....0..8..9.10....0..0..0..0
%e A187593 ..1..0..7..0....0..0..6.10....0..7..1..3....0..2..7..0....1..0..7..8
%e A187593 ..2..0..5..6....2..3..4..5....0..8..6..4....0..3..1..6....2..6..0..9
%e A187593 ..3..4..0..0....0..1..0..0....0..9.10..5....0..4..5..0....3..4..5.10
%K A187593 nonn
%O A187593 1,4
%A A187593 _R. H. Hardin_ Mar 11 2011