A268970 Number of nX7 0..2 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once.

768, 40176, 1770048, 72081792, 2799406656, 105294777120, 3870355944960, 139818682627488, 4983158127443904, 175684152567641184, 6139001133769997952, 212930705454132284064, 7339160588604264574272, 251599271436625798745568

Offset: 1

Author

R. H. Hardin, Feb 16 2016

Keywords

• nonn

Comments

Column 7 of A268971.

Examples

			Some solutions for n=2
..2..2..1..0..1..2..2. .1..2..0..1..0..0..0. .0..1..2..1..0..1..0
..1..0..1..2..1..2..0. .2..1..0..0..0..0..0. .2..1..2..1..2..0..1
		

Links

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

Crossrefs

Cf. A268971.

Formula

Empirical: a(n) = 84*a(n-1) -2466*a(n-2) +31428*a(n-3) -206469*a(n-4) +750384*a(n-5) -1513404*a(n-6) +1574640*a(n-7) -656100*a(n-8)