A220316 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..2 nX2 array

1, 5, 24, 89, 389, 1566, 6401, 25704, 103047, 411453, 1640962, 6538036, 26037222, 103664093, 412658625, 1642555969, 6537717638, 26020883563, 103564418265, 412188609650, 1640510914951, 6529219819790, 25986198727161, 103424615577923

Offset

1,2

Comments

Column 2 of A220319

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) +46*a(n-7) -112*a(n-8) -84*a(n-9) -67*a(n-10) +358*a(n-11) +277*a(n-12) -168*a(n-13) -638*a(n-14) -162*a(n-15) +664*a(n-16) +408*a(n-17) +180*a(n-18) -8*a(n-19) +76*a(n-20) -264*a(n-21) +96*a(n-22)

Example

Some solutions for n=3
..0..0....0..1....0..0....0..1....0..1....1..1....1..1....1..0....1..0....1..0
..0..1....0..0....1..1....1..1....0..0....0..0....1..1....0..0....1..1....0..0
..1..1....1..0....0..0....0..0....0..1....1..1....1..1....0..0....0..0....0..1

Crossrefs

Sequence in context: A270682 A272420 A089095 * A220339 A158499 A074085

Adjacent sequences: A220313 A220314 A220315 * A220317 A220318 A220319

Keyword

nonn

Author

R. H. Hardin Dec 10 2012

Status

approved