A207175 Number of 7 X n 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 0 1 vertically.

14, 196, 546, 3141, 11284, 26866, 98224, 357356, 1032000, 3365824, 11680176, 36617616, 117235264, 392397376, 1266731200, 4070802944, 13377245184, 43530557824, 140684544000, 458843940864, 1494645999616, 4847677870336

Offset

1,1

Comments

Row 7 of A207169.

Links

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

Formula

Empirical: a(n) = a(n-1) + 25*a(n-3) + 6*a(n-4) + 6*a(n-5) - 108*a(n-6) - 72*a(n-7) + 216*a(n-9) for n>11.

Empirical g.f.: x*(14 + 182*x + 350*x^2 + 2245*x^3 + 3159*x^4 + 672*x^5 - 10107*x^6 - 22914*x^7 - 10476*x^8 + 24840*x^9 + 32400*x^10) / (1 - x - 25*x^3 - 6*x^4 - 6*x^5 + 108*x^6 + 72*x^7 - 216*x^9). - Colin Barker, Jun 21 2018

Example

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

Crossrefs

Cf. A207169.

Sequence in context: A208691 A207604 A207030 * A207458 A208004 A207566

Adjacent sequences: A207172 A207173 A207174 * A207176 A207177 A207178

Keyword

nonn

Author

R. H. Hardin, Feb 15 2012

Status

approved