A295093 - OEIS

%I #4 Nov 14 2017 11:14:45

%S 4,24,114,578,2859,14187,70982,353880,1763742,8792075,43834726,

%T 218552639,1089593715,5432145667,27082226021,135020029240,

%U 673148618666,3356010198589,16731535456995,83415827627182,415873350543689

%N Number of nX4 0..1 arrays with each 1 horizontally or vertically adjacent to 1 or 3 1s.

%C Column 4 of A295097.

%H R. H. Hardin, <a href="/A295093/b295093.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) +2*a(n-2) +12*a(n-3) +24*a(n-4) -12*a(n-5) -192*a(n-6) -183*a(n-7) +99*a(n-8) +13*a(n-9) +377*a(n-10) +690*a(n-11) -19*a(n-12) +305*a(n-13) +358*a(n-14) -841*a(n-15) +269*a(n-16) -2630*a(n-17) -190*a(n-18) -818*a(n-19) -1094*a(n-20) +2834*a(n-21) -1033*a(n-22) +1681*a(n-23) +597*a(n-24) +96*a(n-25) +1650*a(n-26) -332*a(n-27) +101*a(n-28) +59*a(n-29) -804*a(n-30) -338*a(n-31) -291*a(n-32) -285*a(n-33) +50*a(n-34) +18*a(n-35) +29*a(n-36) +26*a(n-37) -30*a(n-38) -20*a(n-39) -10*a(n-40) -5*a(n-41) +9*a(n-42) +7*a(n-43) -a(n-44) -a(n-45)

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A295097.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 14 2017