A232078 Number of (2+1) X (n+1) 0..1 arrays with every element equal to some horizontal, diagonal or antidiagonal neighbor, with top left element zero.

11, 87, 520, 3681, 26587, 189404, 1348429, 9607995, 68462448, 487805049, 3475683907, 24764857724, 176453944877, 1257264924795, 8958230513184, 63828946109201, 454792310901883, 3240474086774308, 23088939844648997

Offset

1,1

Links

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

Formula

Empirical: a(n) = 5*a(n-1) + 11*a(n-2) + 23*a(n-3) + 45*a(n-4) + 10*a(n-5) + a(n-6) - 3*a(n-7) - 2*a(n-8).

Empirical g.f.: x*(11 + 32*x - 36*x^2 - 129*x^3 - 34*x^4 - 7*x^5 + 8*x^6 + 6*x^7) / (1 - 5*x - 11*x^2 - 23*x^3 - 45*x^4 - 10*x^5 - x^6 + 3*x^7 + 2*x^8). - Colin Barker, Oct 03 2018

Example

Some solutions for n=6:
..0..0..1..0..0..0..0....0..0..0..1..1..1..1....0..0..0..0..0..0..0
..0..1..1..0..1..1..1....0..0..1..1..1..0..1....0..1..1..1..0..1..0
..1..0..0..1..1..1..1....0..1..0..1..0..1..0....1..0..0..0..1..1..1

Crossrefs

Row 2 of A232076.

Sequence in context: A298253 A277465 A357535 * A016222 A081013 A163616

Adjacent sequences: A232075 A232076 A232077 * A232079 A232080 A232081

Keyword

nonn

Author

R. H. Hardin, Nov 17 2013

Status

approved