A275032 Number of nX3 0..2 arrays with no element equal to any value at offset (0,-1) (-1,-2) or (-2,0) and new values introduced in order 0..2.

2, 16, 46, 146, 450, 1428, 4463, 14086, 44195, 139130, 437175, 1375142, 4323125, 13594852, 42745150, 134409630, 422629291, 1328908089, 4178573479, 13138981872, 41313830121, 129905918777, 408472374963, 1284387955519, 4038591382924

Offset

1,1

Comments

Column 3 of A275037.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +6*a(n-2) -20*a(n-3) -2*a(n-4) +46*a(n-5) -42*a(n-6) -31*a(n-7) +70*a(n-8) -5*a(n-9) -30*a(n-10) -2*a(n-11) +8*a(n-12) +5*a(n-13) -3*a(n-14) -2*a(n-15) +a(n-16) for n>17

Example

Some solutions for n=4
..0..1..0. .0..1..2. .0..1..0. .0..1..2. .0..1..0. .0..1..2. .0..1..0
..0..2..1. .2..0..2. .2..0..2. .1..0..2. .2..0..2. .0..1..2. .2..0..2
..1..0..1. .1..2..0. .1..0..1. .1..2..0. .2..0..1. .2..0..1. .1..2..1
..1..0..2. .0..2..0. .0..1..0. .2..1..0. .0..1..0. .1..0..1. .1..2..0

Crossrefs

Cf. A275037.

Sequence in context: A139267 A254855 A181340 * A295533 A220173 A220801

Adjacent sequences: A275029 A275030 A275031 * A275033 A275034 A275035

Keyword

nonn

Author

R. H. Hardin, Jul 14 2016

Status

approved