|
| |
|
|
A231992
|
|
Number of (n+1) X (2+1) 0..1 arrays with no element having a strict majority of its horizontal and antidiagonal neighbors equal to one.
|
|
1
|
|
|
|
6, 32, 156, 800, 4000, 20228, 101808, 513400, 2586980, 13039568, 65717568, 331222548, 1669362032, 8413644600, 42404958708, 213722166160, 1077165216736, 5428941217444, 27362005944240, 137905229697144, 695045979384260
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
LINKS
|
R. H. Hardin, Table of n, a(n) for n = 1..210
|
|
|
FORMULA
|
Empirical: a(n) = 3*a(n-1) + 12*a(n-2) - 5*a(n-3) - 19*a(n-4) + 2*a(n-5) + 4*a(n-6).
Empirical g.f.: 2*x*(1 + x)*(3 + 4*x - 10*x^2 - x^3 + 2*x^4) / (1 - 3*x - 12*x^2 + 5*x^3 + 19*x^4 - 2*x^5 - 4*x^6). - Colin Barker, Oct 01 2018
|
|
|
EXAMPLE
|
Some solutions for n=7:
..1..0..0....0..0..1....1..0..0....0..0..0....1..0..0....0..0..0....0..0..0
..0..1..0....0..0..0....0..0..0....1..1..0....0..1..0....0..0..1....1..0..1
..1..0..1....0..0..0....1..0..0....0..0..0....1..0..0....0..0..0....0..1..0
..0..0..0....0..1..1....0..0..0....1..0..0....0..0..0....0..1..1....1..0..0
..0..1..0....1..0..0....0..0..0....0..0..0....1..0..1....1..0..0....0..1..1
..1..0..0....0..0..0....1..0..1....0..0..1....0..1..0....0..0..0....0..0..0
..1..0..0....0..0..0....0..0..1....1..0..0....1..0..0....1..0..0....0..0..0
..0..0..1....0..0..0....0..0..0....0..0..0....0..0..1....0..0..0....0..0..0
|
|
|
CROSSREFS
|
Column 2 of A231997.
Sequence in context: A242542 A046725 A232331 * A292044 A006668 A232494
Adjacent sequences: A231989 A231990 A231991 * A231993 A231994 A231995
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
R. H. Hardin, Nov 16 2013
|
|
|
STATUS
|
approved
|
| |
|
|
