A228657 Number of n X 5 binary arrays with top left value 1 and no two ones adjacent horizontally, diagonally or antidiagonally.

5, 38, 335, 2844, 24109, 203762, 1720343, 14516920, 122469941, 1033083774, 8714026943, 73500740436, 619954240797, 5229079954762, 44105207907655, 372009451809136, 3137746452123621, 26465592072488918, 223226285220003247

Offset

1,1

Links

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

Formula

Empirical: a(n) = 12*a(n-1) - 27*a(n-2) - 32*a(n-3) + 49*a(n-4) + 20*a(n-5) - 5*a(n-6).

Empirical g.f.: x*(5 - 22*x + 14*x^2 + 10*x^3 - 3*x^4) / (1 - 12*x + 27*x^2 + 32*x^3 - 49*x^4 - 20*x^5 + 5*x^6). - Colin Barker, Sep 12 2018

Example

Some solutions for n=4:
..1..0..0..0..0....1..0..1..0..1....1..0..1..0..1....1..0..0..0..1
..1..0..1..0..1....1..0..1..0..1....1..0..1..0..0....1..0..0..0..0
..1..0..0..0..1....0..0..0..0..0....1..0..0..0..0....0..0..0..0..1
..1..0..1..0..1....0..0..0..0..1....1..0..0..0..0....0..0..0..0..0

Crossrefs

Column 5 of A228660.

Sequence in context: A247773 A207411 A316598 * A378920 A370476 A369480

Adjacent sequences: A228654 A228655 A228656 * A228658 A228659 A228660

Keyword

nonn

Author

R. H. Hardin, Aug 29 2013

Status

approved