login
Number of nX4 0..1 arrays with every element equal to 1, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.
1

%I #4 Mar 29 2018 12:43:10

%S 2,16,123,947,7326,56710,439078,3399722,26323903,203825456,1578217598,

%T 12220118582,94620225492,732643232114,5672847473255,43924787764759,

%U 340109088005893,2633460459021237,20390851741033347,157886112662767667

%N Number of nX4 0..1 arrays with every element equal to 1, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.

%C Column 4 of A301951.

%H R. H. Hardin, <a href="/A301947/b301947.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 9*a(n-1) -8*a(n-2) -14*a(n-3) +4*a(n-4) +4*a(n-5) -a(n-6)

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A301951.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 29 2018