cp's OEIS Frontend

A241256 Number of 2 X n 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4.

%I A241256 #8 Oct 29 2018 20:31:43
%S A241256 2,5,4,10,12,22,41,59,120,171,306,494,784,1345,2112,3547,5782,9402,
%T A241256 15643,25307,41868,68465,112078,184535,301346,495580,811726,1330658,
%U A241256 2184497,3577622,5872217,9625155,15783147,25889388,42437724,69611469,114132047
%N A241256 Number of 2 X n 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4.
%H A241256 R. H. Hardin, <a href="/A241256/b241256.txt">Table of n, a(n) for n = 1..210</a>
%F A241256 Empirical: a(n) = 2*a(n-2) + 2*a(n-3) - a(n-4) - a(n-5) - a(n-6) + a(n-7) + 2*a(n-8) + a(n-10) for n>12.
%F A241256 Empirical g.f.: x*(2 + 5*x - 4*x^3 - 4*x^4 + x^5 + 8*x^6 + 8*x^7 + 11*x^8 + x^9 + 3*x^10 - 3*x^11) / ((1 + x)*(1 - x - x^2 - x^3 + 2*x^4 - x^5 + 2*x^6 - 3*x^7 + x^8 - x^9)). - _Colin Barker_, Oct 29 2018
%e A241256 Some solutions for n=4:
%e A241256 ..3..3..2..2....2..2..3..3....2..2..3..3....2..2..3..3....2..2..3..3
%e A241256 ..2..1..3..1....3..1..2..1....0..0..0..2....3..1..0..2....0..0..2..1
%Y A241256 Row 2 of A241255.
%K A241256 nonn
%O A241256 1,1
%A A241256 _R. H. Hardin_, Apr 18 2014