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A203980 Number of (n+1) X 5 0..2 arrays with no 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..2 introduced in row major order. 1
384, 5184, 69984, 956448, 13071456, 178855776, 2447270496, 33489653472, 458288894304, 6271519652064, 85823503984224, 1174465206026208, 16072153386090336, 219941927082883296, 3009830115907061856 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A203984.

LINKS

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

FORMULA

Empirical: a(n) = 15*a(n-1) - 270*a(n-3) + 324*a(n-4).

Empirical g.f.: 96*x*(4 - 6*x - 81*x^2 + 108*x^3) / ((1 - 15*x + 18*x^2)*(1 - 18*x^2)). - Colin Barker, Jun 06 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Cf. A203984.

Sequence in context: A252899 A183686 A134241 * A061403 A281656 A128967

Adjacent sequences:  A203977 A203978 A203979 * A203981 A203982 A203983

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 09 2012

STATUS

approved

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Last modified December 4 11:50 EST 2021. Contains 349486 sequences. (Running on oeis4.)