A300772 Number of nX4 0..1 arrays with every element equal to 2, 3, 4 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

0, 4, 11, 36, 179, 735, 3482, 15986, 74347, 346927, 1617399, 7555603, 35285141, 164831052, 770046798, 3597506545, 16807267889, 78522710349, 366856173460, 1713946215073, 8007540142806, 37411176619541, 174784828107456

Offset: 1

Author

R. H. Hardin, Mar 12 2018

Keywords

• nonn

Comments

Column 4 of A300776.

Examples

			Some solutions for n=5
..0..0..0..0. .0..0..0..1. .0..0..0..1. .0..0..0..0. .0..0..0..1
..0..0..1..0. .0..0..1..1. .0..0..1..1. .0..1..1..0. .0..0..1..1
..0..1..1..0. .0..1..0..0. .1..1..0..0. .0..1..0..0. .0..1..1..1
..1..1..0..0. .1..1..0..1. .1..0..0..1. .0..0..1..1. .0..0..0..0
..1..0..0..0. .1..1..1..1. .0..0..1..1. .0..1..1..1. .0..0..0..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Cf. A300776.

Formula

Empirical: a(n) = 7*a(n-1) -9*a(n-2) -8*a(n-3) -4*a(n-4) -15*a(n-5) +109*a(n-6) -99*a(n-7) -458*a(n-8) +1125*a(n-9) +451*a(n-10) -583*a(n-11) +9930*a(n-12) -11717*a(n-13) -15608*a(n-14) +35687*a(n-15) -58043*a(n-16) -57980*a(n-17) +158871*a(n-18) -117558*a(n-19) -9006*a(n-20) +323563*a(n-21) -373476*a(n-22) +364769*a(n-23) -111053*a(n-24) -347366*a(n-25) +535625*a(n-26) -584685*a(n-27) +219534*a(n-28) +20570*a(n-29) -57144*a(n-30) +264924*a(n-31) -292999*a(n-32) +55855*a(n-33) -39233*a(n-34) +197186*a(n-35) -87979*a(n-36) -47711*a(n-37) -8147*a(n-38) +8342*a(n-39) +30624*a(n-40) +6927*a(n-41) -55515*a(n-42) +52943*a(n-43) -29970*a(n-44) +20894*a(n-45) -13250*a(n-46) +3727*a(n-47) -777*a(n-48) +1639*a(n-49) -1592*a(n-50) +674*a(n-51) -130*a(n-52) +20*a(n-53) -13*a(n-54) +6*a(n-55) -a(n-56) for n>57