A296381 - OEIS

%I #4 Dec 11 2017 11:26:40

%S 4,28,127,641,3237,16248,81661,410199,2061212,10356724,52036349,

%T 261457677,1313693921,6600648217,33164941657,166637153693,

%U 837267911142,4206850248548,21137307140110,106204340013363,533623405850063

%N Number of nX3 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 1 or 2 neighboring 1s.

%C Column 3 of A296386.

%H R. H. Hardin, <a href="/A296381/b296381.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5*a(n-1) -2*a(n-2) +14*a(n-3) -20*a(n-4) +24*a(n-5) -52*a(n-6) +83*a(n-7) -82*a(n-8) +43*a(n-9) -5*a(n-10) -4*a(n-11) -9*a(n-12) +19*a(n-13) -15*a(n-14) +6*a(n-15) -a(n-16)

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A296386.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 11 2017