A207600 Number of 3 X n 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 0 1 vertically.

6, 36, 90, 225, 825, 3025, 9240, 28224, 93912, 312481, 997815, 3186225, 10377990, 33802596, 109041570, 351750025, 1140060185, 3695059369, 11948292720, 38635833600, 125075648880, 404906960329, 1310059883431, 4238645087209

Offset

1,1

Comments

Row 3 of A207599.

Links

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

Formula

Empirical: a(n) = a(n-1) -2*a(n-2) +11*a(n-3) +43*a(n-4) +34*a(n-5) +108*a(n-6) -216*a(n-8) -136*a(n-9) -344*a(n-10) -176*a(n-11) +64*a(n-12) -64*a(n-13) +128*a(n-14).

Example

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

Crossrefs

Cf. A207599.

Sequence in context: A207341 A152746 A207363 * A207026 A207171 A207454

Adjacent sequences: A207597 A207598 A207599 * A207601 A207602 A207603

Keyword

nonn

Author

R. H. Hardin, Feb 19 2012

Status

approved