|
|
A202658
|
|
Number of -2..2 arrays of n elements with first through fourth differences also in -2..2
|
|
1
|
|
|
5, 19, 57, 127, 213, 363, 613, 1055, 1815, 3159, 5503, 9609, 16773, 29281, 51125, 89277, 155899, 272315, 475793, 831415, 1452927, 2539213, 4437877, 7756367, 13556573, 23694815, 41415935, 72391801, 126536987, 221182305, 386622379
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = a(n-1) +2*a(n-3) +2*a(n-4) -a(n-5) -2*a(n-7) -a(n-8) -4*a(n-10) -7*a(n-11) -10*a(n-12) -7*a(n-13) -6*a(n-14) -a(n-15) +6*a(n-16) +9*a(n-17) +8*a(n-18) +6*a(n-19) +4*a(n-20) +2*a(n-21) for n>27
|
|
EXAMPLE
|
Some solutions for n=10
.-2...-2....1...-2....0....0...-1....0....0....1...-2....1....0....1...-2....2
..0...-1....2....0...-1....1....1....2....0...-1....0....0...-2....2....0....2
..0....0....2....0....0....0....1....2...-1...-2....1...-1...-2....2....0....1
..0....1....2...-1....1...-1....0....1...-1...-2....2...-1...-2....2...-1....0
..0....1....2...-1....2...-2...-1....0....0...-2....2...-1...-2....2...-2....0
..0....1....2....0....2...-2...-1....0....1...-2....2...-1...-1....1...-2....1
..1....1....1....1....2...-1...-1....0....2...-2....1...-1....1....0...-1....2
..2....0...-1....1....2....0...-1....0....2...-1....0....0....2....0....0....2
..2...-1...-2....1....1....0....0....0....1....0...-1....1....2....0....1....1
..1...-2...-2....0...-1....0....1....1....0....1...-1....0....2...-1....1....0
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|