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A204624 Number of (n+1) X 3 0..2 arrays with every 2 X 2 subblock having unequal diagonal elements or unequal antidiagonal elements, and new values 0..2 introduced in row major order. 1
96, 2049, 43734, 933462, 19923888, 425257068, 9076721064, 193734264456, 4135079723136, 88259474206608, 1883817316421472, 40208348322379872, 858210220662456576, 18317707978060726464, 390974632428061590144 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A204630.

LINKS

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

FORMULA

Empirical: a(n) = 22*a(n-1) -14*a(n-2).

Conjectures from Colin Barker, Jun 07 2018: (Start)

G.f.: 3*x*(32 - 21*x) / (1 - 22*x + 14*x^2).

a(n) = (3*(11+sqrt(107))^n*(31+3*sqrt(107)) + (11-sqrt(107))^n*(-93+9*sqrt(107))) / (4*sqrt(107)).

(End)

EXAMPLE

Some solutions for n=3:

..0..0..0....0..0..1....0..0..1....0..1..2....0..0..1....0..0..1....0..1..0

..0..1..1....2..0..2....2..0..2....1..2..2....2..0..0....2..0..2....2..1..2

..1..2..0....0..0..2....2..2..1....0..2..1....2..0..1....1..0..2....2..1..1

..1..2..1....2..0..2....0..2..1....1..1..0....2..2..2....1..2..1....0..1..2

CROSSREFS

Cf. A204630.

Sequence in context: A159711 A268636 A233153 * A090449 A336677 A233709

Adjacent sequences: A204621 A204622 A204623 * A204625 A204626 A204627

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 17 2012

STATUS

approved

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Last modified December 8 08:53 EST 2022. Contains 358693 sequences. (Running on oeis4.)