A220807 Equals one maps: number of nX3 binary arrays indicating the locations of corresponding elements equal to exactly one of their horizontal, vertical and antidiagonal neighbors in a random 0..2 nX3 array

4, 38, 371, 3466, 30015, 250766, 2050888, 16590068, 133462303, 1070692764, 8577628575, 68669808890, 549555346067, 4397237387636, 35181106306370, 281461795366168, 2251746611140668, 18014183773372344, 144114321357951768

Offset

1,1

Comments

Column 3 of A220810

Links

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

Formula

Empirical: a(n) = 12*a(n-1) -26*a(n-2) -72*a(n-3) +180*a(n-4) +152*a(n-5) -438*a(n-6) -146*a(n-7) +526*a(n-8) +46*a(n-9) -244*a(n-10) +24*a(n-11) +64*a(n-12) for n>20

Example

Some solutions for n=3
..1..0..0....1..0..1....1..0..1....1..0..0....0..0..0....1..0..1....0..1..1
..0..0..1....0..1..1....1..0..0....0..0..1....0..0..1....1..0..0....0..1..0
..0..0..0....1..1..0....1..1..1....0..1..1....0..0..0....0..1..0....1..1..1

Crossrefs

Sequence in context: A092642 A020865 A240378 * A221021 A155859 A220543

Adjacent sequences: A220804 A220805 A220806 * A220808 A220809 A220810

Keyword

nonn

Author

R. H. Hardin Dec 22 2012

Status

approved