cp's OEIS Frontend

A208640 Number of 5 X n 0..1 arrays with new values 0..1 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors.

%I A208640 #9 Jul 05 2018 14:15:27
%S A208640 16,89,284,722,1652,3577,7504,15448,31440,63543,127884,256718,514556,
%T A208640 1030421,2062360,4126468,8254936,16512147,33026868,66056634,132116516,
%U A208640 264236657,528477344,1056959152,2113923232,4227851887,8455709724
%N A208640 Number of 5 X n 0..1 arrays with new values 0..1 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors.
%C A208640 Row 5 of A208637.
%H A208640 R. H. Hardin, <a href="/A208640/b208640.txt">Table of n, a(n) for n = 1..210</a>
%F A208640 Empirical: a(n) = 6*a(n-1) - 14*a(n-2) + 16*a(n-3) - 9*a(n-4) + 2*a(n-5) for n>7.
%F A208640 Conjectures from _Colin Barker_, Jul 05 2018: (Start)
%F A208640 G.f.: x*(16 - 7*x - 26*x^2 + 8*x^3 + 16*x^4 - 2*x^5 - 4*x^6) / ((1 - x)^4*(1 - 2*x)).
%F A208640 a(n) = -84 + 63*2^n - (191*n)/6 - 4*n^2 - n^3/6 for n>2.
%F A208640 (End)
%e A208640 Some solutions for n=4:
%e A208640 ..0..0..0..1....0..1..1..0....0..0..1..0....0..0..0..0....0..0..1..0
%e A208640 ..1..1..0..1....0..0..1..0....1..0..1..0....1..1..1..0....1..0..1..0
%e A208640 ..0..1..0..0....1..0..1..1....1..0..1..0....0..0..1..1....0..1..0..1
%e A208640 ..0..1..1..1....1..0..0..1....1..0..1..0....1..0..0..1....1..0..1..0
%e A208640 ..1..0..0..0....0..1..0..1....1..0..1..0....1..1..0..1....0..1..0..1
%Y A208640 Cf. A208637.
%K A208640 nonn
%O A208640 1,1
%A A208640 _R. H. Hardin_, Feb 29 2012