cp's OEIS Frontend

A239852 Number of n X 2 0..3 arrays with no element equal to zero plus the sum of elements to its left or zero plus the sum of elements above it or one 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 A239852 #7 Oct 26 2018 14:23:30
%S A239852 2,3,5,4,5,5,6,10,11,15,16,21,26,32,41,48,62,74,94,115,142,177,216,
%T A239852 271,331,413,508,629,779,960,1192,1468,1821,2247,2781,3439,4249,5260,
%U A239852 6496,8041,9935,12290,15195,18786,23236,28721,35526,43916,54312,67152,83033
%N A239852 Number of n X 2 0..3 arrays with no element equal to zero plus the sum of elements to its left or zero plus the sum of elements above it or one 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 A239852 R. H. Hardin, <a href="/A239852/b239852.txt">Table of n, a(n) for n = 1..210</a>
%F A239852 Empirical: a(n) = a(n-2) + a(n-5) for n>9.
%F A239852 Empirical g.f.: x*(2 + 3*x + 3*x^2 + x^3 - x^5 - 2*x^6 + x^8) / (1 - x^2 - x^5). - _Colin Barker_, Oct 26 2018
%e A239852 All solutions for n=4:
%e A239852 ..3..2....3..2....3..2....2..3
%e A239852 ..2..3....2..3....2..3....3..0
%e A239852 ..2..0....3..0....3..0....3..2
%e A239852 ..2..0....2..3....3..2....2..3
%Y A239852 Column 2 of A239858.
%K A239852 nonn
%O A239852 1,1
%A A239852 _R. H. Hardin_, Mar 28 2014