A228686 Number of 5 X n binary arrays with no two ones adjacent horizontally, diagonally or antidiagonally.
32, 99, 1277, 6160, 56549, 333517, 2644336, 17124415, 127116873, 859773376, 6193234393, 42741157353, 303661236672, 2115245880075, 14933039299621, 104468526402928, 735366366459485, 5154677670070421, 36235570461792016
Offset: 1
Keywords
Examples
Some solutions for n=4: ..0..0..0..0....0..0..0..1....1..0..1..0....0..1..0..1....0..0..0..0 ..0..0..0..1....0..0..0..1....0..0..1..0....0..1..0..1....1..0..0..0 ..0..1..0..1....0..0..0..0....1..0..0..0....0..0..0..1....0..0..1..0 ..0..1..0..0....1..0..0..0....0..0..0..1....1..0..0..1....1..0..1..0 ..0..0..0..0....0..0..0..1....0..0..0..0....0..0..0..0....0..0..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Row 5 of A228683.
Formula
Empirical: a(n) = 4*a(n-1) + 34*a(n-2) - 76*a(n-3) - 134*a(n-4) + 258*a(n-5) + 45*a(n-6) - 102*a(n-7).
Empirical g.f.: x*(32 - 29*x - 207*x^2 + 118*x^3 + 303*x^4 - 57*x^5 - 102*x^6) / (1 - 4*x - 34*x^2 + 76*x^3 + 134*x^4 - 258*x^5 - 45*x^6 + 102*x^7). - Colin Barker, Sep 12 2018