A185764 Number of (n+1) X 5 binary arrays with no 2 X 2 subblock trace equal to any horizontal or vertical neighbor 2 X 2 subblock trace.

264, 1128, 5272, 24832, 118248, 562800, 2680000, 12760448, 60758008, 289298976, 1377475600, 6558823720, 31229466280, 148698094888, 708018868272, 3371204831376, 16051843045856, 76430201410000, 363919139999024

Offset

1,1

Comments

Column 4 of A185769.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = a(n-1) + 17*a(n-2) + 9*a(n-3) - 22*a(n-4) - a(n-5) + a(n-6) - 6*a(n-7) for n>9.

Empirical g.f.: 8*x*(33 + 108*x - 43*x^2 - 249*x^3 - 69*x^4 + 5*x^5 + 43*x^6 + 81*x^7 + 18*x^8) / (1 - x - 17*x^2 - 9*x^3 + 22*x^4 + x^5 - x^6 + 6*x^7). - Colin Barker, Apr 16 2018

Example

Some solutions for 3 X 5:
..1..0..0..0..0....1..1..1..1..0....1..1..0..1..1....1..1..1..0..1
..1..0..0..1..0....0..0..1..0..1....1..0..1..0..1....1..0..1..0..0
..0..1..1..0..1....0..0..1..1..1....0..1..1..1..0....1..1..0..1..1

Crossrefs

Cf. A185769.

Sequence in context: A160971 A235012 A211713 * A253916 A195672 A123654

Adjacent sequences: A185761 A185762 A185763 * A185765 A185766 A185767

Keyword

nonn

Author

R. H. Hardin, Feb 03 2011

Status

approved