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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.
1
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
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 03 2016
STATUS
approved