login
A214386
Number of 4X4X4 triangular 0..n arrays with no element lying outside the (possibly reversed) range delimited by its sw and se neighbors, and no element equal to its horizontal neighbors
1
16, 890, 11048, 74260, 350232, 1305392, 4107248, 11363940, 28412824, 65439858, 140806952, 286079040, 553378176, 1025850192, 1832212128, 3166557496, 5314833216, 8689668506, 13875533864, 21686539292, 33239546824, 50045674976
OFFSET
1,1
COMMENTS
Row 4 of A214384
LINKS
FORMULA
Empirical: a(n) = (109/226800)*n^10 + (1531/90720)*n^9 + (6911/30240)*n^8 + (4553/3024)*n^7 + (27071/5400)*n^6 + (34159/4320)*n^5 + (409217/90720)*n^4 - (4937/4536)*n^3 - (22087/12600)*n^2 - (43/126)*n
EXAMPLE
Some solutions for n=3
.....3........2........2........2........2........3........2........2
....3.2......1.2......3.0......2.3......2.1......2.3......0.2......1.2
...1.3.0....0.1.2....3.2.0....0.3.2....2.1.2....1.3.0....0.1.2....0.3.2
..0.1.3.0..1.0.3.2..3.0.3.0..0.1.3.1..2.0.1.3..0.3.0.2..0.2.1.2..0.2.3.0
CROSSREFS
Sequence in context: A145243 A264125 A272468 * A367089 A185561 A369583
KEYWORD
nonn
AUTHOR
R. H. Hardin Jul 14 2012
STATUS
approved