A274724 Number of nX4 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.

14, 96, 296, 1632, 9308, 52912, 301784, 1721528, 9816048, 55981988, 319253288, 1820657976, 10382921956, 59212245524, 337678318592, 1925727939552, 10982131736244, 62629418453640, 357165995693576, 2036863060347232

Offset

1,1

Comments

Column 4 of A274728.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +13*a(n-2) +14*a(n-3) +4*a(n-4) -28*a(n-5) -13*a(n-6) -7*a(n-7) +15*a(n-8) for n>12

Example

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

Crossrefs

Cf. A274728.

Sequence in context: A241205 A055844 A308821 * A254469 A372661 A296987

Adjacent sequences: A274721 A274722 A274723 * A274725 A274726 A274727

Keyword

nonn

Author

R. H. Hardin, Jul 03 2016

Status

approved