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A302070 Number of 3Xn 0..1 arrays with every element equal to 0, 1, 2 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero. 1
4, 32, 148, 748, 3657, 18108, 89658, 444359, 2202106, 10912859, 54080195, 268002332, 1328125172, 6581720890, 32616691234, 161636836900, 801015249307, 3969549529089, 19671689743540, 97485967746453, 483106130247259 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 3 of A302069.

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) +4*a(n-2) +2*a(n-3) +7*a(n-4) +7*a(n-5) -4*a(n-6) -10*a(n-7) -3*a(n-8) -5*a(n-9) -11*a(n-10) +2*a(n-11) +8*a(n-12) +a(n-13) -a(n-15) for n>18

EXAMPLE

Some solutions for n=5

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

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

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

CROSSREFS

Cf. A302069.

Sequence in context: A123854 A301843 A332430 * A302267 A113154 A302966

Adjacent sequences:  A302067 A302068 A302069 * A302071 A302072 A302073

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 31 2018

STATUS

approved

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Last modified November 30 05:12 EST 2021. Contains 349419 sequences. (Running on oeis4.)