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A283660 Number of n X 2 0..1 arrays with no element unequal to more than four of its king-move neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards. 1
0, 0, 0, 0, 4, 40, 264, 1504, 7936, 39744, 191552, 896768, 4103616, 18434944, 81563008, 356264448, 1539203584, 6587355136, 27960152064, 117817262080, 493257806848, 2053204985856, 8502296782848, 35043025969152, 143818367385600 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

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

FORMULA

Empirical: a(n) = 12*a(n-1) - 54*a(n-2) + 124*a(n-3) - 204*a(n-4) + 288*a(n-5) - 248*a(n-6) + 240*a(n-7) - 96*a(n-8) + 64*a(n-9).

Empirical g.f.: 4*x^5*(1 - 2*x) / (1 - 4*x + 2*x^2 - 4*x^3)^3. - Colin Barker, Feb 21 2019

EXAMPLE

All solutions for n=5:

..0..0. .0..0. .0..0. .0..0

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

..0..0. .0..0. .0..0. .0..0

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

..0..0. .0..0. .0..0. .0..0

CROSSREFS

Column 2 of A283666.

Sequence in context: A270088 A115286 A119635 * A215701 A212699 A061318

Adjacent sequences:  A283657 A283658 A283659 * A283661 A283662 A283663

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 13 2017

STATUS

approved

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Last modified April 25 16:59 EDT 2019. Contains 322461 sequences. (Running on oeis4.)