cp's OEIS Frontend

A240266 Number of n X 2 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4.

%I A240266 #9 Oct 27 2018 06:25:58
%S A240266 4,7,14,36,72,170,411,879,2106,4874,10808,25648,58383,132428,310199,
%T A240266 704308,1615735,3746472,8529529,19647966,45277950,103456016,238430432,
%U A240266 547803553,1255188579,2890336834,6633676274,15225374578,35023723614
%N A240266 Number of n X 2 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4.
%H A240266 R. H. Hardin, <a href="/A240266/b240266.txt">Table of n, a(n) for n = 1..210</a>
%F A240266 Empirical: a(n) = 2*a(n-2) + 10*a(n-3) - a(n-4) - 5*a(n-5) - 15*a(n-6) + a(n-7) + 4*a(n-8) + 2*a(n-9) + 10*a(n-10) + 5*a(n-11) - 6*a(n-13).
%F A240266 Empirical g.f.: x*(1 + x)*(4 + 3*x + 3*x^2 - 21*x^3 - x^4 - 14*x^5 + 30*x^6 - 4*x^7 + 27*x^8 - x^9 + 2*x^10 - 12*x^11) / (1 - 2*x^2 - 10*x^3 + x^4 + 5*x^5 + 15*x^6 - x^7 - 4*x^8 - 2*x^9 - 10*x^10 - 5*x^11 + 6*x^13). - _Colin Barker_, Oct 27 2018
%e A240266 Some solutions for n=4:
%e A240266 ..3..2....3..2....3..2....3..0....2..3....3..2....3..0....2..0....2..3....3..2
%e A240266 ..3..1....2..1....3..2....3..2....2..1....2..1....2..3....2..0....2..1....3..2
%e A240266 ..2..1....3..2....2..3....2..1....3..0....3..1....3..1....3..2....3..2....2..3
%e A240266 ..2..0....3..1....3..1....2..1....2..3....2..3....3..2....2..1....3..2....3..2
%Y A240266 Column 2 of A240271.
%K A240266 nonn
%O A240266 1,1
%A A240266 _R. H. Hardin_, Apr 03 2014