

A303184


Number of 4Xn 0..1 arrays with every element equal to 0, 1, 2, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.


1



8, 81, 135, 297, 931, 2569, 6668, 17934, 48674, 131037, 353419, 953231, 2569308, 6928326, 18683550, 50378075, 135840557, 366289949, 987683660, 2663241442, 7181313510, 19364081749, 52214352523, 140793629575, 379643605448
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OFFSET

1,1


COMMENTS

Row 4 of A303182.


LINKS

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


FORMULA

Empirical: a(n) = 4*a(n1) 4*a(n2) +4*a(n3) 9*a(n4) +6*a(n5) 5*a(n6) +4*a(n7) 4*a(n8) +14*a(n9) 9*a(n10) 2*a(n12) +8*a(n13) +2*a(n14) 8*a(n15) 4*a(n16) +4*a(n17) for n>22


EXAMPLE

Some solutions for n=5
..0..0..1..0..1. .0..1..0..1..1. .0..1..0..1..0. .0..1..0..1..0
..1..0..1..0..1. .0..1..0..1..0. .0..1..0..0..0. .0..1..0..0..1
..0..0..1..1..1. .0..1..1..1..0. .0..0..0..1..1. .1..0..0..1..0
..0..1..1..0..0. .1..1..0..1..0. .1..1..0..1..0. .0..1..0..1..1


CROSSREFS

Cf. A303182.
Sequence in context: A301939 A302417 A227227 * A302325 A303018 A247536
Adjacent sequences: A303181 A303182 A303183 * A303185 A303186 A303187


KEYWORD

nonn


AUTHOR

R. H. Hardin, Apr 19 2018


STATUS

approved



