A232670 Number of (n+1) X (1+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally, vertically, diagonally or antidiagonally.

36, 212, 1568, 11878, 87680, 651678, 4846056, 35990386, 267429284, 1987124934, 14763908592, 109698051138, 815067420300, 6055993810126, 44996556671640, 334327945984154, 2484081968889732, 18456924487924070, 137136383652862288

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + 21*a(n-2) + 118*a(n-3) + 170*a(n-4) + 166*a(n-5) - 52*a(n-6) - 48*a(n-7) - 64*a(n-8).

Empirical g.f.: 2*x*(18 + 70*x + 194*x^2 + 21*x^3 - 70*x^4 - 80*x^5 - 32*x^6) / (1 - 2*x - 21*x^2 - 118*x^3 - 170*x^4 - 166*x^5 + 52*x^6 + 48*x^7 + 64*x^8). - Colin Barker, Oct 05 2018

Example

Some solutions for n=5:
..2..1....0..2....2..1....1..2....0..2....2..1....1..2....1..2....0..2....0..1
..1..0....0..1....1..0....1..0....1..0....1..0....2..0....0..1....1..2....2..1
..2..0....2..0....2..0....1..0....2..2....0..0....0..0....0..0....2..1....1..1
..0..2....2..0....2..1....0..2....2..1....2..1....1..0....2..1....0..1....0..2
..0..1....1..0....2..0....0..2....0..1....2..0....1..2....0..1....1..1....1..2
..2..2....0..2....2..1....0..1....2..2....1..0....2..0....1..2....2..2....2..0

Crossrefs

Column 1 of A232677.

Sequence in context: A361209 A144523 A232677 * A365308 A230470 A066610

Adjacent sequences: A232667 A232668 A232669 * A232671 A232672 A232673

Keyword

nonn

Author

R. H. Hardin, Nov 27 2013

Status

approved