A303085 Number of 3Xn 0..1 arrays with every element equal to 0, 2, 3, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

4, 2, 32, 29, 258, 432, 2525, 6313, 30188, 97855, 428478, 1605301, 6821375, 27390903, 115569231, 478335810, 2017576268, 8457463080, 35707225807, 150472100292, 635822248364, 2685274511197, 11352580693193, 47989709554314

Offset: 1

Author

R. H. Hardin, Apr 18 2018

Keywords

• nonn

Comments

Row 3 of A303084.

Examples

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

Links

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

Crossrefs

Cf. A303084.

Formula

Empirical: a(n) = 7*a(n-1) -2*a(n-2) -67*a(n-3) +80*a(n-4) +187*a(n-5) -202*a(n-6) -298*a(n-7) +122*a(n-8) +213*a(n-9) +122*a(n-10) +126*a(n-11) -63*a(n-12) -416*a(n-13) +152*a(n-14) +20*a(n-15) -21*a(n-16) +9*a(n-17) for n>18