cp's OEIS Frontend

A187293 Number of 8-step one or two space at a time rook's tours on an n X n board summed over all starting positions.

%I A187293 #9 Jul 22 2025 10:41:14
%S A187293 0,0,2664,134944,866888,2732016,6049424,10906120,17282088,25129488,
%T A187293 34417440,45129696,57260948,70809512,85775112,102157696,119957264,
%U A187293 139173816,159807352,181857872,205325376,230209864,256511336,284229792
%N A187293 Number of 8-step one or two space at a time rook's tours on an n X n board summed over all starting positions.
%C A187293 Row 8 of A187286
%H A187293 R. H. Hardin, <a href="/A187293/b187293.txt">Table of n, a(n) for n = 1..50</a>
%F A187293 Empirical: a(n) = 708492*n^2 - 5580668*n + 10074432 for n>13
%e A187293 Some solutions for 4X4
%e A187293 ..0..5..1..0....0..5..6..0....5..4..6..3....0..0..0..6....3..2..0..1
%e A187293 ..0..6..2..0....8..4..7..3....0..0..7..1....0..8..0..7....0..0..0..0
%e A187293 ..0..4..3..0....0..0..0..2....0..0..8..2....0..3..4..5....4..0..0..8
%e A187293 ..0..7..0..8....0..0..0..1....0..0..0..0....0..2..1..0....5..6..0..7
%K A187293 nonn
%O A187293 1,3
%A A187293 _R. H. Hardin_ Mar 08 2011