A240514 - OEIS

A240514

Number of nX3 0..1 arrays with no element equal to exactly two horizontal and vertical neighbors, with new values 0..1 introduced in row major order

3, 6, 10, 28, 73, 196, 515, 1376, 3686, 9914, 26681, 71876, 193749, 522510, 1409414, 3802164, 10257707, 27675148, 74669353, 201466240, 543583450, 1466670482, 3957312647, 10677488468, 28809678971, 77733469590, 209738364682

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OFFSET

1,1

COMMENTS

Column 3 of A240519

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) -3*a(n-2) -2*a(n-3) +2*a(n-4) +2*a(n-5) -7*a(n-6) -8*a(n-7) +15*a(n-8) +4*a(n-9) -8*a(n-10) -4*a(n-11) +15*a(n-12) +8*a(n-13) -7*a(n-14) -2*a(n-15) +2*a(n-16) +2*a(n-17) -3*a(n-18) -4*a(n-19) -a(n-20)

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A116544 A110891 A197435 * A115887 A068195 A080506

Adjacent sequences: A240511 A240512 A240513 * A240515 A240516 A240517

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 06 2014

STATUS

approved