A208416 Number of n X 4 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 0 and 0 1 1 vertically.

10, 100, 378, 1269, 3835, 10098, 26375, 65178, 157734, 378262, 891503, 2096679, 4903388, 11430925, 26635182, 61947132, 144056682, 334894773, 778319859, 1809079118, 4204482395, 9772110046, 22713444310, 52793388462, 122714964255

Offset

1,1

Comments

Column 4 of A208420.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -10*a(n-3) -15*a(n-4) +40*a(n-5) +19*a(n-6) -25*a(n-7) -60*a(n-8) +32*a(n-9) -10*a(n-10) +29*a(n-11) +28*a(n-12) +43*a(n-13) -83*a(n-14) -24*a(n-15) +4*a(n-16) +30*a(n-17) -13*a(n-18) +20*a(n-19) +a(n-20) -3*a(n-21) -8*a(n-22) +4*a(n-23) -2*a(n-24) -a(n-25) +a(n-27).

Example

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

Crossrefs

Cf. A208420.

Sequence in context: A207859 A207809 A208283 * A208024 A207804 A060522

Adjacent sequences: A208413 A208414 A208415 * A208417 A208418 A208419

Keyword

nonn

Author

R. H. Hardin, Feb 26 2012

Status

approved