A208144 Number of 5Xn 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically

10, 100, 450, 2025, 6300, 19600, 49000, 122500, 264600, 571536, 1111320, 2160900, 3880800, 6969600, 11761200, 19847025, 31853250, 51122500, 78728650, 121242121, 180360180, 268304400, 387550800, 559795600, 788351200, 1110222400, 1529388000

Offset

1,1

Comments

Row 5 of A208142

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +8*a(n-2) -18*a(n-3) -27*a(n-4) +72*a(n-5) +48*a(n-6) -168*a(n-7) -42*a(n-8) +252*a(n-9) -252*a(n-11) +42*a(n-12) +168*a(n-13) -48*a(n-14) -72*a(n-15) +27*a(n-16) +18*a(n-17) -8*a(n-18) -2*a(n-19) +a(n-20)

Example

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

Crossrefs

Sequence in context: A207251 A208289 A208365 * A207713 A222716 A111434

Adjacent sequences: A208141 A208142 A208143 * A208145 A208146 A208147

Keyword

nonn

Author

R. H. Hardin Feb 23 2012

Status

approved