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

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

R. H. Hardin, Table of n, a(n) for n = 1..163

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

Adjacent sequences: A214383 A214384 A214385 * A214387 A214388 A214389

Keyword

nonn

Author

R. H. Hardin Jul 14 2012

Status

approved