A268738 Number of nX6 binary arrays with some 1 horizontally or vertically adjacent to some other 1 exactly once.

20, 420, 7831, 128232, 1971414, 29134076, 418632185, 5894815754, 81718671716, 1119014223138, 15171181272721, 203998929406004, 2724149465085496, 36163754541884778, 477648079847735215, 6280858615510607492

Offset: 1

Author

R. H. Hardin, Feb 12 2016

Keywords

• nonn

Comments

Column 6 of A268740.

Examples

			Some solutions for n=4
..0..0..0..0..1..0. .0..0..0..0..1..0. .1..0..0..0..0..1. .0..0..1..1..0..0
..0..0..1..0..0..0. .0..1..0..0..0..0. .0..1..0..0..0..0. .0..1..0..0..1..0
..1..0..0..0..0..0. .1..0..0..0..0..0. .1..0..0..1..0..0. .0..0..0..0..0..0
..0..0..1..1..0..0. .1..0..1..0..1..0. .1..0..0..0..0..1. .0..0..0..0..0..1
		

Links

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

Crossrefs

Cf. A268740.

Formula

Empirical: a(n) = 16*a(n-1) +60*a(n-2) -1148*a(n-3) -3346*a(n-4) +16272*a(n-5) +36588*a(n-6) -104246*a(n-7) -147989*a(n-8) +349140*a(n-9) +217324*a(n-10) -591448*a(n-11) -19320*a(n-12) +431032*a(n-13) -151921*a(n-14) -73194*a(n-15) +41684*a(n-16) +2552*a(n-17) -3594*a(n-18) +148*a(n-19) +100*a(n-20) -4*a(n-21) -a(n-22)