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A203981 Number of (n+1) X 6 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
1536, 31104, 629856, 13071456, 271918944, 5671161216, 118333620576, 2469841766784, 51553851826176, 1076137623724896, 22463572543638624, 468912308350736736, 9788249148960940416, 204323642334833818464 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 5 of A203984.

LINKS

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

FORMULA

Empirical: a(n) = 25*a(n-1) - 45*a(n-2) - 963*a(n-3) + 2025*a(n-4) + 3645*a(n-5) - 6561*a(n-6).

Empirical g.f.: 96*x*(16 - 76*x - 819*x^2 + 2124*x^3 + 3321*x^4 - 6561*x^5) / ((1 - 25*x + 90*x^2 - 81*x^3)*(1 - 45*x^2 - 81*x^3)). - Colin Barker, Jun 06 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Cf. A203984.

Sequence in context: A179692 A105923 A229507 * A188788 A170793 A224068

Adjacent sequences:  A203978 A203979 A203980 * A203982 A203983 A203984

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 09 2012

STATUS

approved

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Last modified October 16 13:48 EDT 2021. Contains 348042 sequences. (Running on oeis4.)