A219398 Unchanging value maps: number of n X 3 binary arrays indicating the locations of corresponding elements unequal to no king-move neighbor in a random 0..1 n X 3 array

4, 4, 16, 43, 122, 345, 979, 2791, 7936, 22540, 64031, 181974, 517221, 1469927, 4177203, 11870804, 33735384, 95872371, 272457370, 774287065, 2200420843, 6253312335, 17771112208, 50503204860, 143523553079, 407875327102

Offset

1,1

Comments

Column 3 of A219403.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) - 2*a(n-2) + 3*a(n-3) + 4*a(n-4) + 2*a(n-5) - 5*a(n-6) - 2*a(n-7) for n>8.

Empirical g.f.: x*(4 - 8*x + 12*x^2 - 9*x^3 - 3*x^4 - 7*x^5 + 7*x^6 + 2*x^7) / (1 - 3*x + 2*x^2 - 3*x^3 - 4*x^4 - 2*x^5 + 5*x^6 + 2*x^7). - Colin Barker, Mar 11 2018

Example

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

Crossrefs

Cf. A219403.

Sequence in context: A218051 A092266 A257606 * A222104 A257613 A223202

Adjacent sequences: A219395 A219396 A219397 * A219399 A219400 A219401

Keyword

nonn

Author

R. H. Hardin, Nov 19 2012

Status

approved