A271037 Number of 5X5X5 triangular 0..n arrays with some element less than a w, nw or ne neighbor exactly once.

98, 2420, 29120, 232432, 1402082, 6872424, 28658242, 104918592, 344970188, 1036183048, 2880940360, 7491977248, 18376721948, 42808972960, 95252409300, 203411012288, 418599114270, 833032325020, 1607950467240, 3018338301840

Offset

1,1

Comments

Row 5 of A271034.

Links

R. H. Hardin, Table of n, a(n) for n = 1..43

Formula

Empirical: a(n) = (271/59439744000)*n^15 + (13547/43589145600)*n^14 + (13957/1437004800)*n^13 + (88289/479001600)*n^12 + (17036507/7185024000)*n^11 + (190313/8709120)*n^10 + (135902587/914457600)*n^9 + (230644919/304819200)*n^8 + (134986897/46656000)*n^7 + (89816651/10886400)*n^6 + (281267579/16329600)*n^5 + (23798177/935550)*n^4 + (394130917/15765750)*n^3 + (137477173/9459450)*n^2 + (12932/3465)*n

Example

Some solutions for n=3
......0..........0..........0..........0..........0..........1..........0
.....0.1........0.1........0.1........1.1........0.0........1.1........0.0
....1.1.1......0.3.3......0.1.1......1.2.2......0.1.1......1.2.2......1.1.1
...1.1.2.2....0.0.3.3....0.1.2.1....0.2.2.2....0.1.1.1....2.2.2.2....1.2.2.1
..1.3.3.2.3..2.3.3.3.3..0.2.2.2.2..3.3.3.3.3..3.2.3.3.3..2.2.3.2.2..2.2.3.3.3

Crossrefs

Cf. A271034.

Sequence in context: A022149 A128801 A188484 * A243477 A178974 A233920

Adjacent sequences: A271034 A271035 A271036 * A271038 A271039 A271040

Keyword

nonn

Author

R. H. Hardin, Mar 29 2016

Status

approved