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A204566 Number of (n+1) X 3 0..3 arrays with every 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..3 introduced in row major order. 1
42, 482, 6112, 80518, 1075080, 14421190, 193752824, 2604524150, 35017728648, 470841185510, 6330966828952, 85127273980246, 1144638803080104, 15391060969557190, 206951592970169528, 2782716926395505462 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A204572.

LINKS

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

FORMULA

Empirical: a(n) = 19*a(n-1) - 79*a(n-2) + 57*a(n-3) + 16*a(n-4) - 12*a(n-5).

Empirical g.f.: 2*x*(21 - 158*x + 136*x^2 + 37*x^3 - 30*x^4) / ((1 - x)*(1 - 5*x + 2*x^2)*(1 - 13*x - 6*x^2)). - Colin Barker, Jun 07 2018

EXAMPLE

Some solutions for n=4:

..0..0..0....0..0..0....0..1..0....0..1..0....0..1..1....0..0..0....0..0..1

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

..1..0..1....2..0..0....1..1..0....0..2..0....3..2..0....1..0..0....3..2..0

..0..1..0....3..2..0....0..1..1....1..0..1....2..0..0....0..0..2....0..3..2

..1..0..0....1..3..2....1..0..1....3..1..0....1..2..0....0..0..0....1..0..3

CROSSREFS

Cf. A204572.

Sequence in context: A216109 A216111 A216113 * A249233 A249234 A250324

Adjacent sequences:  A204563 A204564 A204565 * A204567 A204568 A204569

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 16 2012

STATUS

approved

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Last modified January 19 03:54 EST 2020. Contains 331031 sequences. (Running on oeis4.)