cp's OEIS Frontend

A240187 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 three plus the sum of the elements diagonally to its northwest, modulo 4.

%I A240187 #8 Oct 27 2018 06:21:17
%S A240187 1,5,12,27,73,154,358,872,1871,4438,10338,22880,54100,123711,279854,
%T A240187 655190,1491102,3413413,7919449,18045604,41514375,95741087,218782546,
%U A240187 503899032,1158409848,2653808377,6109601340,14027233372,32187863462
%N A240187 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 three plus the sum of the elements diagonally to its northwest, modulo 4.
%H A240187 R. H. Hardin, <a href="/A240187/b240187.txt">Table of n, a(n) for n = 1..210</a>
%F A240187 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 A240187 Empirical g.f.: x*(1 + 5*x + 10*x^2 + 7*x^3 - 10*x^5 - 6*x^6 - 5*x^7 - 6*x^8 + 4*x^9 + 4*x^10 + 6*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 A240187 Some solutions for n=4:
%e A240187 ..2..0....2..0....2..0....2..0....2..0....2..0....2..0....2..0....2..0....2..0
%e A240187 ..1..0....1..0....1..3....2..0....2..0....1..3....1..3....2..0....2..3....1..3
%e A240187 ..2..3....2..3....1..2....2..0....2..3....2..1....2..3....2..0....2..3....2..3
%e A240187 ..1..2....1..3....2..3....1..0....2..3....1..2....1..0....2..0....1..0....1..2
%Y A240187 Column 2 of A240192.
%K A240187 nonn
%O A240187 1,2
%A A240187 _R. H. Hardin_, Apr 02 2014