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A220339 Equals two maps: number of nX2 binary arrays indicating the locations of corresponding elements equal to exactly two of their king-move neighbors in a random 0..3 nX2 array 1
1, 5, 24, 89, 389, 1570, 6413, 25744, 103229, 412081, 1643706, 6548560, 26080372, 103836793, 413362985, 1645415613, 6549395074, 26068520679, 103759005831, 412983036406, 1643754108417, 6542452940294, 26040170803581, 103644625748031 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 2 of A220342

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) +6*a(n-2) -22*a(n-3) -15*a(n-4) +10*a(n-5) +56*a(n-6) +34*a(n-7) -68*a(n-8) -12*a(n-9) -247*a(n-10) +258*a(n-11) +429*a(n-12) -176*a(n-13) -798*a(n-14) +50*a(n-15) +1112*a(n-16) -368*a(n-17) -628*a(n-18) +288*a(n-19) -56*a(n-20) -248*a(n-21) +96*a(n-22)

EXAMPLE

Some solutions for n=3

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

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

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

CROSSREFS

Sequence in context: A272420 A089095 A220316 * A158499 A074085 A145914

Adjacent sequences:  A220336 A220337 A220338 * A220340 A220341 A220342

KEYWORD

nonn

AUTHOR

R. H. Hardin Dec 11 2012

STATUS

approved

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Last modified September 17 07:51 EDT 2021. Contains 347478 sequences. (Running on oeis4.)