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A280551 Number of nX5 0..1 arrays with no element equal to more than one of its horizontal and vertical neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards. 1
2, 87, 325, 832, 1764, 3438, 6386, 11506, 20389, 35757, 62317, 108150, 187115, 322925, 556071, 955574, 1638882, 2805542, 4794088, 8178068, 13927945, 23683803, 40214243, 68187902, 115469449, 195294823, 329919371, 556731676, 938492304 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 5 of A280554.

LINKS

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

FORMULA

Empirical: a(n) = 6*a(n-1) -12*a(n-2) +5*a(n-3) +12*a(n-4) -12*a(n-5) -3*a(n-6) +6*a(n-7) -a(n-9) for n>12

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Cf. A280554.

Sequence in context: A306139 A317372 A177318 * A283945 A172736 A244386

Adjacent sequences:  A280548 A280549 A280550 * A280552 A280553 A280554

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 05 2017

STATUS

approved

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Last modified December 13 15:03 EST 2018. Contains 318086 sequences. (Running on oeis4.)