A216939 Number of side-3 hexagonal 0..n arrays with values nondecreasing E, SW and SE

52, 1211, 17336, 175869, 1374208, 8737047, 46978360, 219784500, 914221308, 3438633452, 11853180096, 37855195604, 113017101804, 317780021548, 846830343064, 2150149059905, 5225497612280, 12203607643755, 27481596234600

Offset

1,1

Comments

Row 3 of A216937

Links

R. H. Hardin, Table of n, a(n) for n = 1..50

Formula

Empirical: a(n) = (1/5884534656000)*n^19 + (19/1176906931200)*n^18 + (2063/2853107712000)*n^17 + (127381/6276836966400)*n^16 + (3139187/7846046208000)*n^15 + (23993/4075868160)*n^14 + (3154906109/47076277248000)*n^13 + (437462609/724250419200)*n^12 + (2639011847/603542016000)*n^11 + (281346697/10973491200)*n^10 + (295058425993/2414168064000)*n^9 + (32651688991/68976230400)*n^8 + (158599063783/106991539200)*n^7 + (1749363777247/470762772480)*n^6 + (177682359077/24216192000)*n^5 + (26456060689/2377589760)*n^4 + (113155260151/9081072000)*n^3 + (178973011/18532800)*n^2 + (275861/60060)*n + 1

Example

Some solutions for n=3
......0.0.0..........0.1.2..........0.1.1..........0.0.0..........0.0.0
.....0.1.2.3........1.2.2.2........0.1.1.3........0.0.0.0........0.0.0.3
....0.1.2.3.3......2.2.2.2.2......1.1.2.3.3......0.0.1.1.3......1.1.2.3.3
.....2.2.3.3........2.2.2.3........1.3.3.3........1.1.1.3........1.2.3.3
......2.3.3..........2.3.3..........3.3.3..........3.3.3..........2.3.3

Crossrefs

Sequence in context: A160288 A133238 A331127 * A130000 A160153 A017768

Adjacent sequences: A216936 A216937 A216938 * A216940 A216941 A216942

Keyword

nonn

Author

R. H. Hardin Sep 20 2012

Status

approved