A219058 Hilltop maps: number of nX3 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal, diagonal or antidiagonal neighbor in a random 0..2 nX3 array

7, 63, 503, 4017, 32123, 256849, 2053803, 16422459, 131315929, 1050017821, 8396067527, 67135955941, 536827099717, 4292533426183, 34323608522733, 274455661738997, 2194580159330181, 17548124331666509, 140316892162923409

Offset

1,1

Comments

Column 3 of A219063

Links

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

Formula

Empirical: a(n) = 7*a(n-1) +7*a(n-2) +7*a(n-3) +3*a(n-4) +21*a(n-5) +6*a(n-6) +6*a(n-7) +3*a(n-8) +9*a(n-9) -9*a(n-10) -9*a(n-11) -9*a(n-12) -9*a(n-13)

Example

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

Crossrefs

Sequence in context: A165759 A166153 A123009 * A182603 A320073 A218191

Adjacent sequences: A219055 A219056 A219057 * A219059 A219060 A219061

Keyword

nonn

Author

R. H. Hardin Nov 11 2012

Status

approved