A207939 Number of 3 X n 0..1 arrays avoiding 0 0 1 and 1 0 0 horizontally and 0 0 1 and 1 1 0 vertically.

6, 36, 98, 271, 844, 2706, 8977, 30168, 102384, 349069, 1193648, 4087980, 14013419, 48061824, 164886926, 565777111, 1941543632, 6663053798, 22867234785, 78480570100, 269349014868, 924424358989, 3172699693492, 10888986998392

Offset

1,1

Comments

Row 3 of A207938.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) - a(n-2) - 20*a(n-3) + 10*a(n-4) + 28*a(n-5) - 9*a(n-6) - 15*a(n-7) + a(n-8) + 2*a(n-9) for n>10.

Empirical g.f.: x*(6 + 6*x - 76*x^2 - 63*x^3 + 247*x^4 + 189*x^5 - 223*x^6 - 171*x^7 + 29*x^8 + 26*x^9) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 - x - x^2)*(1 - 2*x - 5*x^2 + x^4)). - Colin Barker, Mar 06 2018

Example

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

Crossrefs

Cf. A207938.

Sequence in context: A207306 A207112 A207392 * A207462 A086113 A207903

Adjacent sequences: A207936 A207937 A207938 * A207940 A207941 A207942

Keyword

nonn

Author

R. H. Hardin, Feb 21 2012

Status

approved