A269074 Number of nX7 binary arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two not more than once.

72, 1204, 27042, 542112, 10778640, 210476400, 4064720816, 77785162880, 1477636398784, 27897108860960, 523921783242624, 9794822341611072, 182387895832407680, 3384281324193062016, 62600172035227164032

Offset: 1

Author

R. H. Hardin, Feb 19 2016

Keywords

• nonn

Comments

Column 7 of A269075.

Examples

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

Links

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

Crossrefs

Cf. A269075.

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