cp's OEIS Frontend

A208410 Number of 3 X n 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.

%I A208410 #8 Jul 02 2018 14:13:20
%S A208410 5,187,10682,658450,40883360,2540446156,157873031498,9810914663050,
%T A208410 609693293454056,37889020302613060,2354590230800815490,
%U A208410 146324584692741696562,9093252748398554214416,565094688091663621180732
%N A208410 Number of 3 X n 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.
%C A208410 Row 3 of A208408.
%H A208410 R. H. Hardin, <a href="/A208410/b208410.txt">Table of n, a(n) for n = 1..210</a>
%F A208410 Empirical: a(n) = 62*a(n-1) + 39*a(n-2) - 1790*a(n-3) - 4703*a(n-4) - 1254*a(n-5) + 3249*a(n-6) + 918*a(n-7) - 648*a(n-8) for n>10.
%F A208410 Empirical g.f.: x*(1 + x)*(2 - 23*x - 3*x^2 + 22*x^3 + 8*x^4) / ((1 - 3*x - 2*x^2)*(1 - 15*x - 12*x^2)). - _Colin Barker_, Jul 02 2018
%e A208410 Some solutions for n=4:
%e A208410 ..0..0..0..0....0..0..1..0....0..1..1..1....0..1..1..1....0..0..0..0
%e A208410 ..0..1..1..2....0..0..0..0....0..2..3..0....0..0..0..1....0..1..0..0
%e A208410 ..0..1..0..0....1..1..1..0....1..1..1..1....0..1..0..0....1..2..3..2
%Y A208410 Cf. A208408.
%K A208410 nonn
%O A208410 1,1
%A A208410 _R. H. Hardin_, Feb 26 2012