A274730 Number of 5 X n 0..2 arrays with no element equal to any value at offset (-1,-2) (-2,-1) or (-1,0) and new values introduced in order 0..2.

8, 144, 1040, 9308, 84948, 771300, 7016284, 63780144, 579907180, 5272264616, 47934377596, 435805897172, 3962236677384, 36023613993928, 327517339347916, 2977702208511048, 27072492754395896, 246136048094770872

Offset

1,1

Links

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

Formula

Empirical: a(n) = 10*a(n-1) - a(n-2) - 80*a(n-3) + 133*a(n-4) - 49*a(n-5) - 16*a(n-6) + 4*a(n-7) for n>9.

Empirical g.f.: 4*x*(2 + 16*x - 98*x^2 - 77*x^3 + 841*x^4 - 1108*x^5 + 434*x^6 - 72*x^7 + 24*x^8) / ((1 - x)*(1 - 9*x - 8*x^2 + 72*x^3 - 61*x^4 - 12*x^5 + 4*x^6)). - Colin Barker, Jan 30 2019

Example

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

Crossrefs

Row 5 of A274728.

Sequence in context: A275139 A370071 A241229 * A263604 A212703 A065409

Adjacent sequences: A274727 A274728 A274729 * A274731 A274732 A274733

Keyword

nonn

Author

R. H. Hardin, Jul 03 2016

Status

approved