A214354 Number of 4X4X4 triangular 0..n arrays with no element lying outside the (possibly reversed) range delimited by its sw and se neighbors.

160, 2853, 23554, 127813, 529006, 1807653, 5349708, 14150061, 34190300, 76678305, 161533230, 322614617, 615330522, 1127418361, 1993875448, 3417225641, 5694545880, 9252943437, 14695473146, 22859815485, 34892402886, 52341084797

Offset: 1

Author

R. H. Hardin Jul 13 2012

Keywords

• nonn

Comments

Row 4 of A214352

Examples

			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
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

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