A228801 Number of 6Xn binary arrays with top left element equal to 1 and no two ones adjacent horizontally or nw-se.

32, 89, 2892, 22060, 362511, 3835792, 51557716, 607251543, 7672139244, 93420773609, 1159188543069, 14247881349908, 175944344684763, 2167769734896816, 26737779597736284, 329618632980267413

Offset

1,1

Comments

Row 6 of A228796

Links

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

Formula

Empirical: a(n) = a(n-1) +119*a(n-2) +397*a(n-3) -1395*a(n-4) -5213*a(n-5) +8797*a(n-6) +24443*a(n-7) -36756*a(n-8) -45888*a(n-9) +84092*a(n-10) +19388*a(n-11) -83412*a(n-12) +24912*a(n-13) +22741*a(n-14) -12257*a(n-15) -1459*a(n-16) +1607*a(n-17) -49*a(n-18) -71*a(n-19) +3*a(n-20) +a(n-21)

Example

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

Crossrefs

Sequence in context: A318341 A318073 A279713 * A220581 A297730 A360436

Adjacent sequences: A228798 A228799 A228800 * A228802 A228803 A228804

Keyword

nonn

Author

R. H. Hardin Sep 04 2013

Status

approved