cp's OEIS Frontend

A241301 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 zero 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 A241301 #9 Oct 29 2018 20:16:12
%S A241301 2,6,6,12,16,28,38,66,92,154,222,362,532,854,1272,2018,3036,4776,7236,
%T A241301 11316,17230,26832,41000,63658,97516,151086,231858,358688,551144,
%U A241301 851718,1309890,2022722,3112810,4804190,7396624,11411300,17574716,27106414
%N A241301 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 zero 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 A241301 R. H. Hardin, <a href="/A241301/b241301.txt">Table of n, a(n) for n = 1..210</a>
%F A241301 Empirical: a(n) = 2*a(n-2) + a(n-3) - a(n-5).
%F A241301 Empirical g.f.: 2*x*(1 + 3*x + x^2 - x^3 - x^4) / (1 - 2*x^2 - x^3 + x^5). - _Colin Barker_, Oct 29 2018
%e A241301 Some solutions for n=4:
%e A241301 ..3..2....2..3....3..2....2..3....3..2....3..2....2..3....3..2....2..3....3..2
%e A241301 ..3..1....2..3....1..2....2..1....3..2....3..2....1..3....1..2....2..1....1..2
%e A241301 ..2..1....2..1....3..2....2..3....1..2....1..2....1..2....3..2....2..3....3..2
%e A241301 ..2..3....2..1....3..2....1..3....1..2....3..2....3..2....3..1....2..3....1..2
%Y A241301 Column 2 of A241306.
%K A241301 nonn
%O A241301 1,1
%A A241301 _R. H. Hardin_, Apr 18 2014