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A221930 Number of 2Xn arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, without move-in move-out straight through or left turns 1
1, 25, 232, 2197, 20933, 198589, 1885324, 17896442, 169874679, 1612469540, 15305706000, 145283086944, 1379039583394, 13089962041815, 124251041949203, 1179401540313291, 11194980504773785, 106263714435179508 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row 2 of A221929

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..55

FORMULA

Empirical: a(n) = 9*a(n-1) +10*a(n-2) -45*a(n-3) -57*a(n-4) +45*a(n-5) -3*a(n-6) -616*a(n-7) -57*a(n-8) +1200*a(n-9) -268*a(n-10) -289*a(n-11) -9*a(n-12) +6*a(n-13)

EXAMPLE

Some solutions for n=3

..1..2..0....2..1..0....0..0..1....0..0..1....0..1..2....2..2..1....1..1..3

..0..3..0....1..1..1....0..5..0....0..3..2....0..2..1....0..1..0....0..0..1

CROSSREFS

Sequence in context: A053919 A053927 A081195 * A160222 A088890 A108178

Adjacent sequences:  A221927 A221928 A221929 * A221931 A221932 A221933

KEYWORD

nonn

AUTHOR

R. H. Hardin Feb 01 2013

STATUS

approved

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Last modified January 28 23:12 EST 2022. Contains 350670 sequences. (Running on oeis4.)