A297520 - OEIS

%I #8 Mar 01 2019 06:21:00

%S 1,5,17,33,65,193,529,1185,2737,7169,18257,43425,104945,264001,656785,

%T 1597665,3913009,9708161,23980241,58804257,144593009,357011905,

%U 879991825,2164014945,5327178673,13131288833,32347250513,79624144545,196075443953

%N Number of 2 X n 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 3 neighboring 1s.

%H R. H. Hardin, <a href="/A297520/b297520.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) + 4*a(n-3) + 12*a(n-4).

%F Empirical g.f.: x*(1 + 4*x + 12*x^2 + 12*x^3) / (1 - x - 4*x^3 - 12*x^4). - _Colin Barker_, Mar 01 2019

%e Some solutions for n=7:

%e ..1..1..0..0..0..1..1. .1..0..0..0..1..1..0. .0..0..0..0..0..0..0

%e ..1..0..1..0..1..0..1. .0..1..0..0..1..0..1. .1..1..0..0..0..0..0

%Y Row 2 of A297519.

%K nonn

%O 1,2

%A _R. H. Hardin_, Dec 31 2017