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A240632 Number of nX4 0..1 arrays with no element equal to exactly three horizontal or vertical neighbors, with new values 0..1 introduced in row major order 1
8, 81, 637, 4989, 38634, 299329, 2319211, 17971509, 139264013, 1079178635, 8362717691, 64803934520, 502175240181, 3891429932618, 30155264060461, 233677585671980, 1810802052546549, 14032171994804298, 108737368953561194 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A240636

LINKS

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

FORMULA

Empirical: a(n) = 7*a(n-1) +7*a(n-2) -9*a(n-3) -3*a(n-4) +6*a(n-5) +11*a(n-6) +56*a(n-7) -211*a(n-8) -553*a(n-9) -266*a(n-10) +569*a(n-11) +514*a(n-12) +241*a(n-13) +672*a(n-14) +985*a(n-15) +518*a(n-16) +71*a(n-17) -161*a(n-18) -845*a(n-19) -670*a(n-20) -783*a(n-21) -620*a(n-22) -263*a(n-23) +134*a(n-24) +196*a(n-25) +238*a(n-26) +159*a(n-27) +70*a(n-28) +5*a(n-29) -14*a(n-30) -18*a(n-31) -8*a(n-32)

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A343274 A240480 A274752 * A007792 A301837 A264185

Adjacent sequences:  A240629 A240630 A240631 * A240633 A240634 A240635

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 09 2014

STATUS

approved

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Last modified August 13 05:18 EDT 2022. Contains 356077 sequences. (Running on oeis4.)