A220250 Sum of neighbor maps: number of nX2 binary arrays indicating the locations of corresponding elements equal to the sum mod 3 of their king-move neighbors in a random 0..2 nX2 array

2, 16, 48, 256, 928, 4096, 15872, 65536, 259584, 1048576, 4182016, 16777216, 67051520, 268435456, 1073479680, 4294967296, 17178689536, 68719476736, 274872664064, 1099511627776, 4398023442432, 17592186044416, 70368643514368

Offset

1,1

Comments

Column 2 of A220254

Links

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

Formula

Empirical: a(n)=4*a(n-1)+8*a(n-2)-32*a(n-3)-16*a(n-4)+64*a(n-5)

a(n) = 4^n - 2^(n-2)*(n+1)*(1-(-1)^n). - Vaclav Kotesovec, Jul 06 2013

Example

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

Crossrefs

Sequence in context: A295533 A220173 A220801 * A192388 A162442 A159010

Adjacent sequences: A220247 A220248 A220249 * A220251 A220252 A220253

Keyword

nonn

Author

R. H. Hardin Dec 08 2012

Status

approved