A219144 Unchanging value maps: number of 3Xn binary arrays indicating the locations of corresponding elements unequal to no horizontal, diagonal or antidiagonal neighbor in a random 0..2 3Xn array

1, 18, 78, 281, 1072, 4033, 15255, 57963, 220068, 835820, 3172817, 12044346, 45722019, 173574485, 658947323, 2501581220, 9496787730, 36052730049, 136867284190, 519590670019, 1972527813429, 7488329193659, 28428025632710

Offset

1,2

Comments

Row 3 of A219142

Links

R. H. Hardin, Table of n, a(n) for n = 1..40

Formula

Empirical: a(n) = 4*a(n-1) -8*a(n-3) +17*a(n-4) +17*a(n-5) -29*a(n-6) -13*a(n-7) +9*a(n-8) -31*a(n-9) -26*a(n-10) +30*a(n-11) -3*a(n-12) +6*a(n-13) +17*a(n-14) -3*a(n-15) +3*a(n-16) -2*a(n-17) for n>18

Example

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

Crossrefs

Sequence in context: A197886 A039453 A342560 * A063495 A264850 A039408

Adjacent sequences: A219141 A219142 A219143 * A219145 A219146 A219147

Keyword

nonn

Author

R. H. Hardin Nov 12 2012

Status

approved