A297721 - OEIS

%I #4 Jan 04 2018 21:59:59

%S 1,10,34,83,258,865,2651,8041,25114,78356,242335,750668,2331147,

%T 7233125,22428585,69571574,215837630,669523807,2076792418,6442276953,

%U 19984194983,61990893369,192295766302,596503969480,1850361240315,5739832532268

%N Number of 2Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1, 2 or 4 neighboring 1s.

%C Row 2 of A297720.

%H R. H. Hardin, <a href="/A297721/b297721.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) -3*a(n-2) +3*a(n-3) -2*a(n-4) -24*a(n-5) +24*a(n-6)

%e Some solutions for n=7

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

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

%Y Cf. A297720.

%K nonn

%O 1,2

%A _R. H. Hardin_, Jan 04 2018