A268994 Number of nX7 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

72, 2037, 57287, 1506570, 38241770, 946498448, 22995344760, 550731432312, 13040291111728, 305911647779632, 7121104059933536, 164688437285444064, 3787495455529375808, 86684333527271203264, 1975573336154420926848

Offset: 1

Author

R. H. Hardin, Feb 17 2016

Keywords

• nonn

Comments

Column 7 of A268995.

Examples

			Some solutions for n=3
..0..0..0..1..0..0..0. .0..0..1..0..0..0..1. .1..0..0..0..1..0..1
..0..0..0..0..0..0..0. .1..0..0..0..1..0..1. .0..0..1..0..0..0..0
..0..1..1..0..1..0..0. .0..0..0..0..0..0..0. .1..0..0..0..1..0..0
		

Links

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

Crossrefs

Cf. A268995.

Formula

Empirical: a(n) = 68*a(n-1) -1804*a(n-2) +24560*a(n-3) -195400*a(n-4) +974752*a(n-5) -3171360*a(n-6) +6871936*a(n-7) -9999248*a(n-8) +9740096*a(n-9) -6250176*a(n-10) +2552576*a(n-11) -621824*a(n-12) +79872*a(n-13) -4096*a(n-14) for n>16