cp's OEIS Frontend

A241050 Number of n X 2 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.

%I A241050 #9 Oct 29 2018 07:16:57
%S A241050 3,3,4,6,8,12,13,20,28,38,53,68,96,130,178,245,330,454,617,841,1153,
%T A241050 1563,2144,2913,3982,5431,7404,10111,13783,18809,25665,34995,47772,
%U A241050 65135,88894,121250,165416,225685,307854,420020,572988,781677,1066446,1454794
%N A241050 Number of n X 2 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.
%H A241050 R. H. Hardin, <a href="/A241050/b241050.txt">Table of n, a(n) for n = 1..210</a>
%F A241050 Empirical: a(n) = 2*a(n-2) - a(n-4) + a(n-5) - a(n-7) + a(n-8) + a(n-11) for n>15.
%F A241050 Empirical g.f.: x*(3 + 3*x - 2*x^2 + 3*x^4 - 2*x^6 + x^7 + 4*x^8 + 3*x^9 - 2*x^11 - x^12 + x^13 + 2*x^14) / ((1 + x)*(1 - x - x^2 + x^3 - x^5 + x^6 - x^8 + x^9 - x^10)). - _Colin Barker_, Oct 29 2018
%e A241050 All solutions for n=4:
%e A241050 ..3..2....3..3....3..3....3..2....3..2....3..2
%e A241050 ..2..0....2..0....2..2....2..0....2..0....2..0
%e A241050 ..3..3....2..0....2..0....3..3....2..0....3..3
%e A241050 ..3..2....2..0....2..0....2..2....2..0....2..0
%Y A241050 Column 2 of A241054.
%K A241050 nonn
%O A241050 1,1
%A A241050 _R. H. Hardin_, Apr 15 2014