# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a239650 Showing 1-1 of 1 %I A239650 #7 Oct 26 2018 11:18:32 %S A239650 4,20,92,418,1898,8588,38888,175974,796550,3604984,16316908,73849786, %T A239650 334252546,1512838756,6847231728,30990953678,140267248638, %U A239650 634858320528,2873411390324,13005245181090,58862597882746,266415951317884 %N A239650 Number of 2 X n 0..3 arrays with no element equal to zero plus the sum of elements to its left or two plus the sum of the elements above it, modulo 4. %H A239650 R. H. Hardin, Table of n, a(n) for n = 1..210 %F A239650 Empirical: a(n) = 3*a(n-1) + 12*a(n-2) - 18*a(n-3) - 29*a(n-4) + 19*a(n-5) + 38*a(n-6) + 8*a(n-7). %F A239650 Empirical g.f.: 2*x*(2 + 4*x - 8*x^2 - 13*x^3 + 8*x^4 + 19*x^5 + 4*x^6) / (1 - 3*x - 12*x^2 + 18*x^3 + 29*x^4 - 19*x^5 - 38*x^6 - 8*x^7). - _Colin Barker_, Oct 26 2018 %e A239650 Some solutions for n=5: %e A239650 ..1..3..1..0..0....1..3..3..0..1....3..1..1..3..1....1..3..1..0..3 %e A239650 ..2..3..0..0..3....1..0..0..0..2....3..1..2..3..0....2..0..1..0..0 %Y A239650 Row 2 of A239649. %K A239650 nonn %O A239650 1,1 %A A239650 _R. H. Hardin_, Mar 23 2014 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE