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A240515 Number of nX4 0..1 arrays with no element equal to exactly two horizontal and vertical neighbors, with new values 0..1 introduced in row major order 1
5, 10, 28, 99, 326, 1080, 3765, 13282, 46928, 166611, 595402, 2132856, 7647821, 27453594, 98644580, 354622219, 1275200926, 4586567656, 16499401997, 59359672578, 213570572184, 768440651027, 2764982991218, 9949082534056 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A240519

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-1) -5*a(n-2) +4*a(n-3) -3*a(n-4) -49*a(n-5) +10*a(n-6) +15*a(n-7) +45*a(n-8) +124*a(n-9) +131*a(n-10) +301*a(n-11) +18*a(n-12) -615*a(n-13) -201*a(n-14) -1508*a(n-15) -823*a(n-16) -413*a(n-17) -254*a(n-18) +2467*a(n-19) +793*a(n-20) +4516*a(n-21) +1071*a(n-22) +2289*a(n-23) -2289*a(n-25) -1071*a(n-26) -4516*a(n-27) -793*a(n-28) -2467*a(n-29) +254*a(n-30) +413*a(n-31) +823*a(n-32) +1508*a(n-33) +201*a(n-34) +615*a(n-35) -18*a(n-36) -301*a(n-37) -131*a(n-38) -124*a(n-39) -45*a(n-40) -15*a(n-41) -10*a(n-42) +49*a(n-43) +3*a(n-44) -4*a(n-45) +5*a(n-46) -5*a(n-47) +a(n-48)

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A054298 A022094 A134129 * A105862 A093029 A105505

Adjacent sequences:  A240512 A240513 A240514 * A240516 A240517 A240518

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 06 2014

STATUS

approved

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Last modified April 13 09:12 EDT 2021. Contains 342935 sequences. (Running on oeis4.)