|
%I #8 Aug 15 2018 12:37:53
%S 4,46,530,6108,70394,811286,9350020,107758398,1241908834,14312922076,
%T 164955536810,1901102303238,21910085816324,252512376457166,
%U 2910189435065650,33539752256081628,386543558932945114
%N Number of n X 2 0..5 arrays with entries increasing mod 6 by 0, 1, 2 or 3 rightwards and downwards, starting with upper left zero.
%C Column 2 of A222104.
%H R. H. Hardin, <a href="/A222098/b222098.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 13*a(n-1) - 17*a(n-2).
%F Conjectures from _Colin Barker_, Aug 15 2018: (Start)
%F G.f.: 2*x*(2 - 3*x) / (1 - 13*x + 17*x^2).
%F a(n) = (2^(-n)*((13-sqrt(101))^n*(-29+3*sqrt(101)) + (13+sqrt(101))^n*(29+3*sqrt(101)))) / (17*sqrt(101)).
%F (End)
%e Some solutions for n=3:
%e ..0..1....0..3....0..3....0..0....0..0....0..3....0..3....0..0....0..2....0..2
%e ..0..1....3..0....3..3....3..0....0..1....2..4....3..0....3..3....2..3....1..3
%e ..0..1....5..0....0..0....0..2....2..3....2..4....4..1....3..0....4..5....4..4
%Y Cf. A222104.
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 07 2013
| 