

A281606


Number of 3Xn 0..2 arrays with no element equal to more than one of its horizontal, diagonal or antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.


1



5, 50, 209, 1283, 8180, 49572, 302304, 1849212, 11295326, 69003066, 421598546, 2575763454, 15736620000, 96143466614, 587391366384, 3588683849428, 21925168436114, 133952450888038, 818386359248384, 4999955088202190
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OFFSET

1,1


COMMENTS

Row 3 of A281605.


LINKS

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


FORMULA

Empirical: a(n) = 6*a(n1) 4*a(n2) +29*a(n3) 15*a(n4) +73*a(n5) +11*a(n6) 32*a(n7) +6*a(n8) +a(n9) 30*a(n10) 26*a(n11) +10*a(n12) +8*a(n13) for n>15


EXAMPLE

Some solutions for n=4
..0..1..0..1. .0..1..0..1. .0..1..0..2. .0..1..2..1. .0..1..1..0
..2..1..2..1. .0..1..2..1. .0..2..0..2. .1..2..0..1. .2..0..2..2
..2..0..2..0. .2..1..0..0. .1..2..0..1. .0..2..0..2. .2..1..1..0


CROSSREFS

Cf. A281605.
Sequence in context: A069540 A267640 A238650 * A061160 A226548 A274064
Adjacent sequences: A281603 A281604 A281605 * A281607 A281608 A281609


KEYWORD

nonn


AUTHOR

R. H. Hardin, Jan 25 2017


STATUS

approved



