A232840 Number of (1+1) X (n+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally, diagonally or antidiagonally.

4, 16, 216, 710, 3648, 25642, 139456, 683250, 3950740, 22616130, 120525288, 658213410, 3693117580, 20305930298, 110933224304, 613037501594, 3386085231380, 18604669612418, 102411236923656, 564815468453874

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + 3*a(n-2) + 66*a(n-3) + 150*a(n-4) - 86*a(n-5) - 36*a(n-6) - 176*a(n-7) - 512*a(n-8).

Empirical g.f.: 2*x*(2 + 4*x + 86*x^2 - 17*x^3 - 38*x^4 - 48*x^5 - 256*x^6) / (1 - 2*x - 3*x^2 - 66*x^3 - 150*x^4 + 86*x^5 + 36*x^6 + 176*x^7 + 512*x^8). - Colin Barker, Oct 06 2018

Example

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

Crossrefs

Row 1 of A232839.

Sequence in context: A088027 A271267 A333438 * A113905 A200045 A099202

Adjacent sequences: A232837 A232838 A232839 * A232841 A232842 A232843

Keyword

nonn

Author

R. H. Hardin, Nov 30 2013

Status

approved