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A283786 Number of 3Xn 0..1 arrays with no 1 equal to more than two of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly two elements. 1
0, 1, 60, 625, 5432, 43793, 336614, 2456405, 17337452, 119568097, 807400279, 5361533627, 35121018814, 227356916503, 1456991303945, 9255597126444, 58345386218659, 365301459240939, 2273330797518109, 14070544563651381 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Row 3 of A283784.

LINKS

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

FORMULA

Empirical: a(n) = 15*a(n-1) -66*a(n-2) +80*a(n-3) -468*a(n-4) +3087*a(n-5) -2637*a(n-6) +1521*a(n-7) -48147*a(n-8) +47343*a(n-9) +81669*a(n-10) +252723*a(n-11) -449826*a(n-12) -859263*a(n-13) +209880*a(n-14) +2012553*a(n-15) +1838166*a(n-16) -3525918*a(n-17) -3408930*a(n-18) +1213335*a(n-19) +5670018*a(n-20) +961731*a(n-21) -5692641*a(n-22) -258915*a(n-23) +1572148*a(n-24) +2087043*a(n-25) -2057643*a(n-26) -530461*a(n-27) +1830090*a(n-28) -1416102*a(n-29) +615644*a(n-30) -172620*a(n-31) +29400*a(n-32) -2744*a(n-33)

EXAMPLE

Some solutions for n=4

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

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

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

CROSSREFS

Cf. A283784.

Sequence in context: A229750 A223338 A081384 * A099344 A324068 A223242

Adjacent sequences:  A283783 A283784 A283785 * A283787 A283788 A283789

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 16 2017

STATUS

approved

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Last modified May 28 15:04 EDT 2022. Contains 354115 sequences. (Running on oeis4.)