A228389 Number of nX7 binary arrays with top left value 1 and no two ones adjacent horizontally or vertically.

13, 169, 3513, 62546, 1177709, 21683149, 402968942, 7458864720, 138305554175, 2562514124813, 47494743530686, 880148347563002, 16311635295084771, 302290762813484314, 5602201879906920864, 103822064306056848780

Offset

1,1

Comments

Column 7 of A228390

Links

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

Formula

Empirical: a(n) = 9*a(n-1) +203*a(n-2) -210*a(n-3) -5659*a(n-4) +6975*a(n-5) +48558*a(n-6) -82823*a(n-7) -127405*a(n-8) +308107*a(n-9) +21372*a(n-10) -340142*a(n-11) +100779*a(n-12) +139011*a(n-13) -54187*a(n-14) -25564*a(n-15) +9369*a(n-16) +2227*a(n-17) -546*a(n-18) -87*a(n-19) +9*a(n-20) +a(n-21)

Example

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

Crossrefs

Sequence in context: A045600 A001022 A195945 * A020533 A176596 A176023

Adjacent sequences: A228386 A228387 A228388 * A228390 A228391 A228392

Keyword

nonn

Author

R. H. Hardin Aug 21 2013

Status

approved