|
|
A214354
|
|
Number of 4X4X4 triangular 0..n arrays with no element lying outside the (possibly reversed) range delimited by its sw and se neighbors
|
|
1
|
|
|
160, 2853, 23554, 127813, 529006, 1807653, 5349708, 14150061, 34190300, 76678305, 161533230, 322614617, 615330522, 1127418361, 1993875448, 3417225641, 5694545880, 9252943437, 14695473146, 22859815485, 34892402886, 52341084797
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
Empirical: a(n) = (109/226800)*n^10 + (1531/90720)*n^9 + (1471/6048)*n^8 + (28627/15120)*n^7 + (47321/5400)*n^6 + (107767/4320)*n^5 + (789913/18144)*n^4 + (127789/2835)*n^3 + (111121/4200)*n^2 + (5083/630)*n + 1
|
|
EXAMPLE
|
Some solutions for n=3
.....2........2........1........2........0........2........2........1
....2.2......3.1......0.3......2.1......0.0......3.2......2.1......1.2
...3.0.2....3.1.2....0.0.3....2.1.2....0.0.0....1.3.0....3.1.3....0.2.2
..3.0.2.1..3.0.2.1..0.0.3.1..3.0.2.2..1.0.0.3..1.3.0.1..3.0.3.1..0.1.3.2
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|