A183339 Number of nX7 binary arrays with each 1 adjacent to exactly one 1 vertically and one 1 horizontally

1, 13, 37, 97, 407, 1397, 4531, 16029, 55471, 188735, 651517, 2246015, 7712899, 26544813, 91374201, 314289321, 1081352347, 3720918175, 12801778315, 44045879629, 151549077973, 521423489151, 1794025850189, 6172623965117

Offset

1,2

Comments

Equivalent to all 1s connected only in 2X2 blocks

Column 7 of A183342

Links

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

Formula

Empirical: a(n)=a(n-1)+2*a(n-2)+18*a(n-3)+17*a(n-4)+7*a(n-5)-40*a(n-6)-78*a(n-7)-21*a(n-8)+88*a(n-9)+62*a(n-10)-49*a(n-11)-24*a(n-12)+9*a(n-13)-18*a(n-14)+2*a(n-15)+9*a(n-16)+4*a(n-17)+4*a(n-18)

Example

Some solutions for 5X7
..0..0..0..1..1..0..0....1..1..0..0..0..0..0....0..0..0..0..1..1..0
..0..0..0..1..1..0..0....1..1..0..0..1..1..0....1..1..0..0..1..1..0
..0..0..0..0..0..1..1....0..0..0..0..1..1..0....1..1..0..0..0..0..0
..1..1..0..0..0..1..1....0..0..0..0..0..0..0....0..0..1..1..0..0..0
..1..1..0..0..0..0..0....0..0..0..0..0..0..0....0..0..1..1..0..0..0

Crossrefs

Sequence in context: A317986 A043190 A043970 * A331763 A155263 A155228

Adjacent sequences: A183336 A183337 A183338 * A183340 A183341 A183342

Keyword

nonn

Author

R. H. Hardin Jan 04 2011

Status

approved