cp's OEIS Frontend

A297721 Number of 2Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1, 2 or 4 neighboring 1s.

%I A297721 #4 Jan 04 2018 21:59:59
%S A297721 1,10,34,83,258,865,2651,8041,25114,78356,242335,750668,2331147,
%T A297721 7233125,22428585,69571574,215837630,669523807,2076792418,6442276953,
%U A297721 19984194983,61990893369,192295766302,596503969480,1850361240315,5739832532268
%N A297721 Number of 2Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1, 2 or 4 neighboring 1s.
%C A297721 Row 2 of A297720.
%H A297721 R. H. Hardin, <a href="/A297721/b297721.txt">Table of n, a(n) for n = 1..210</a>
%F A297721 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 A297721 Some solutions for n=7
%e A297721 ..1..1..0..1..1..0..0. .0..0..1..0..1..1..1. .0..1..0..1..1..0..0
%e A297721 ..1..1..0..0..0..1..1. .0..0..1..1..1..0..1. .1..0..0..1..0..0..0
%Y A297721 Cf. A297720.
%K A297721 nonn
%O A297721 1,2
%A A297721 _R. H. Hardin_, Jan 04 2018