cp's OEIS Frontend

A241278 Number of nX2 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 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 A241278 #6 Jun 02 2025 10:03:09
%S A241278 3,3,9,36,139,532,2111,8473,34053,136880,550213,2211810,8891567,
%T A241278 35744766,143696235,577666729,2322248891,9335550407,37529342193,
%U A241278 150869654682,606502776180,2438168211361,9801544653549,39402644818707,158400380771179
%N A241278 Number of nX2 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 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.
%C A241278 Column 2 of A241283
%H A241278 R. H. Hardin, <a href="/A241278/b241278.txt">Table of n, a(n) for n = 1..210</a>
%F A241278 Empirical: a(n) = 8*a(n-1) -20*a(n-2) +16*a(n-3) +4*a(n-4) -25*a(n-5) +53*a(n-6) -68*a(n-7) +100*a(n-8) -62*a(n-9) -41*a(n-10) +34*a(n-11) -117*a(n-12) +108*a(n-13) -54*a(n-14) +93*a(n-15) +41*a(n-16) +20*a(n-17) +8*a(n-18) -41*a(n-19) -26*a(n-20) -41*a(n-21) +9*a(n-22) +5*a(n-23) +2*a(n-24) +4*a(n-25) -13*a(n-26) +4*a(n-27) -3*a(n-28) -2*a(n-29) +4*a(n-30) +a(n-31)
%e A241278 Some solutions for n=4
%e A241278 ..3..2....3..3....2..2....3..3....3..3....3..3....3..2....3..3....2..2....3..3
%e A241278 ..0..3....2..2....0..0....2..2....2..2....2..2....0..3....2..2....0..0....2..2
%e A241278 ..2..0....0..0....3..3....0..2....2..2....2..2....2..0....0..0....0..3....2..2
%e A241278 ..2..2....2..2....3..3....0..2....0..2....2..0....2..0....0..2....3..3....0..0
%K A241278 nonn
%O A241278 1,1
%A A241278 _R. H. Hardin_, Apr 18 2014