cp's OEIS Frontend

A189179 Number of n X 2 array permutations with each element making a single king move.

%I A189179 #11 Mar 01 2018 05:35:08
%S A189179 1,9,33,185,913,4777,24577,127385,658801,3410313,17648609,91343481,
%T A189179 472746833,2446730345,12663143361,65538688857,339198332209,
%U A189179 1755536122697,9085854920609,47024245778489,243376070611729,1259603657442857
%N A189179 Number of n X 2 array permutations with each element making a single king move.
%C A189179 Column 2 of A189186.
%H A189179 R. H. Hardin, <a href="/A189179/b189179.txt">Table of n, a(n) for n = 1..200</a>
%F A189179 Empirical: a(n) = 5*a(n-1) + 4*a(n-2) - 16*a(n-3).
%F A189179 Empirical g.f.: x*(1 + 4*x - 16*x^2) / (1 - 5*x - 4*x^2 + 16*x^3). - _Colin Barker_, Mar 01 2018
%e A189179 Some solutions for 3 X 2:
%e A189179 ..1..0....1..2....2..0....2..0....1..0....1..2....3..0....2..3....3..2....3..0
%e A189179 ..3..4....5..0....4..1....3..1....4..5....0..5....5..1....0..1....0..1....4..1
%e A189179 ..5..2....3..4....5..3....5..4....2..3....3..4....2..4....5..4....5..4....5..2
%Y A189179 Cf. A189186.
%K A189179 nonn
%O A189179 1,2
%A A189179 _R. H. Hardin_, Apr 18 2011