|
|
A228215
|
|
Number of second differences of arrays of length n+2 of numbers in 0..5
|
|
2
|
|
|
21, 271, 2731, 23351, 176851, 1225631, 8006491, 50556551, 313882531, 1932641711, 11839990891, 72260648471, 439667406451, 2668522016831, 16163719991611, 97745259402791, 590286253682371, 3560791008422351, 21460113482174731
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = 11*a(n-1) -30*a(n-2) for n>11
|
|
EXAMPLE
|
Some solutions for n=4
..1....2...-1...-7...-4..-10...-6....1....2....8...-3....2...-6...-3....5....6
.-4....2...-3....5....0....8....5....2...-5...-2....1...-2....8....0...-3...-9
..1...-2...-1...-1....7...-3....2....0....4...-3....4....6...-1....3...-1....5
..5....3....6....2...-5...-2...-3....5....3....5...-8...-5...-5...-1....6....3
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|