|
| |
|
|
A317857
|
|
Number of nX2 0..1 arrays with every element unequal to 1, 2 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
|
|
3
|
|
|
|
1, 3, 6, 10, 21, 46, 102, 220, 491, 1077, 2393, 5271, 11682, 25799, 57090, 126209, 279123, 617274, 1364930, 3018713, 6675002, 14762294, 32643544, 72191407, 159639957, 353036505, 780698639, 1726457594, 3817890631, 8442936930
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
COMMENTS
|
Column 2 of A317863.
|
|
|
LINKS
|
R. H. Hardin, Table of n, a(n) for n = 1..210
|
|
|
FORMULA
|
Empirical: a(n) = a(n-1) +4*a(n-2) -2*a(n-3) -2*a(n-4) +a(n-5) -4*a(n-6) +4*a(n-7) -a(n-8)
|
|
|
EXAMPLE
|
Some solutions for n=5
..0..0. .0..1. .0..0. .0..1. .0..0. .0..0. .0..1. .0..1. .0..0. .0..1
..1..0. .0..1. .1..0. .1..0. .1..0. .1..1. .1..1. .1..1. .1..1. .1..1
..0..0. .0..1. .0..0. .1..1. .0..0. .1..1. .0..1. .0..0. .1..0. .1..0
..1..0. .0..1. .0..1. .0..1. .1..1. .0..1. .1..0. .0..0. .1..1. .0..0
..0..1. .0..1. .0..0. .1..0. .1..0. .1..0. .1..1. .1..1. .1..0. .0..1
|
|
|
CROSSREFS
|
Cf. A317863.
Sequence in context: A068709 A068804 A117834 * A220827 A063015 A282515
Adjacent sequences: A317854 A317855 A317856 * A317858 A317859 A317860
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
R. H. Hardin, Aug 09 2018
|
|
|
STATUS
|
approved
|
| |
|
|
