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A283517 Number of nX3 0..1 arrays with no 1 equal to more than three of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly two elements. 1
0, 1, 20, 270, 2763, 26662, 241796, 2115564, 18020972, 150431216, 1235860816, 10022560088, 80412418752, 639331124272, 5043680344120, 39521427506168, 307850445104320, 2385411084242780, 18397022091700304, 141285768645661084 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Column 3 of A283522.

LINKS

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

FORMULA

Empirical: a(n) = 15*a(n-1) -36*a(n-2) -235*a(n-3) +171*a(n-4) +2481*a(n-5) +5734*a(n-6) +6894*a(n-7) +5364*a(n-8) +3397*a(n-9) +1947*a(n-10) +846*a(n-11) +277*a(n-12) +126*a(n-13) +12*a(n-14) +8*a(n-15) for n>19

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Cf. A283522.

Sequence in context: A125455 A019928 A025934 * A180799 A021594 A224248

Adjacent sequences:  A283514 A283515 A283516 * A283518 A283519 A283520

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 09 2017

STATUS

approved

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Last modified April 21 10:03 EDT 2019. Contains 322328 sequences. (Running on oeis4.)