cp's OEIS Frontend

A241357 Number of 2Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or one 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 A241357 #6 Jun 02 2025 10:06:33
%S A241357 3,3,9,17,23,53,103,160,344,643,1059,2196,4039,6930,13970,25512,45059,
%T A241357 88830,161841,291573,565051,1029968,1879844,3596548,6568902,12087395,
%U A241357 22908471,41950860,77573588,146021963,268115989,497179651,931373038
%N A241357 Number of 2Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4.
%C A241357 Row 2 of A241356
%H A241357 R. H. Hardin, <a href="/A241357/b241357.txt">Table of n, a(n) for n = 1..210</a>
%F A241357 Empirical: a(n) = a(n-2) +8*a(n-3) -5*a(n-5) -18*a(n-6) +a(n-7) +10*a(n-8) +16*a(n-9) -5*a(n-10) -10*a(n-11) +a(n-12) +6*a(n-13) -2*a(n-14) -6*a(n-15) -a(n-16) +6*a(n-17) for n>20
%e A241357 Some solutions for n=4
%e A241357 ..2..3..3..2....2..3..3..2....2..3..3..3....3..2..3..3....3..2..3..3
%e A241357 ..2..1..1..1....2..1..1..2....2..1..2..3....3..1..1..3....3..2..2..1
%K A241357 nonn
%O A241357 1,1
%A A241357 _R. H. Hardin_, Apr 20 2014