A269010 Number of nX7 binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

38, 696, 18210, 390064, 8134304, 164351184, 3258530608, 63679868768, 1230707111424, 23573013881888, 448188039743360, 8468276406290880, 159151109503787520, 2977237536021550208, 55469798154343791232

Offset: 1

Author

R. H. Hardin, Feb 17 2016

Keywords

• nonn

Comments

Column 7 of A269011.

Examples

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

Links

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

Crossrefs

Cf. A269011.

Formula

Empirical: a(n) = 60*a(n-1) -1352*a(n-2) +13344*a(n-3) -35948*a(n-4) -311480*a(n-5) +1985472*a(n-6) +1821840*a(n-7) -31021776*a(n-8) +4125984*a(n-9) [phone]*a(n-10) -46853056*a(n-11) -1173410880*a(n-12) -138650624*a(n-13) [phone]*a(n-14) [phone]*a(n-15) -3360870400*a(n-16) -2339016704*a(n-17) [phone]*a(n-18) [phone]*a(n-19) -291553280*a(n-20) -245170176*a(n-21) [phone]*a(n-22) [phone]*a(n-23) -4194304*a(n-24) for n>25