A252874 Number of n X 6 nonnegative integer arrays with upper left 0 and lower right n+6-4 and value increasing by 0 or 1 with every step right or down.

10, 120, 949, 5281, 23203, 85801, 277585, 806347, 2142634, 5281314, 12207123, 26687363, 55571337, 110851465, 212839721, 394940091, 710658874, 1243696244, 2122211729, 3538661109, 5776971495, 9249264713, 14544867193, 22494968931

Offset

1,1

Comments

Column 6 of A252876.

Links

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

Formula

Empirical: a(n) = (1/11404800)*n^12 + (1/211200)*n^11 + (37/345600)*n^10 + (143/103680)*n^9 + (27977/2419200)*n^8 + (83399/1209600)*n^7 + (318253/1036800)*n^6 + (6655/6912)*n^5 + (17647/9600)*n^4 + (350243/129600)*n^3 + (95119/277200)*n^2 + (5297/6930)*n + 3.

Empirical: G.f.: -x*(10 -10*x +169*x^2 -556*x^3 +1402*x^4 -2404*x^5 +2895*x^6 -2526*x^7 +1599*x^8 -716*x^9 +214*x^10 -38*x^11 +3*x^12) / (x-1)^13. - R. J. Mathar, Nov 21 2015

Example

Some solutions for n=3:
..0..1..2..2..3..3....0..1..2..3..3..4....0..1..1..2..2..3....0..0..1..2..3..4
..1..2..2..3..4..4....1..2..2..3..4..4....1..1..1..2..3..4....1..1..1..2..3..4
..1..2..2..3..4..5....2..2..3..4..5..5....1..1..2..3..4..5....2..2..2..3..4..5

Crossrefs

Sequence in context: A226767 A307620 A300522 * A182605 A024127 A005949

Adjacent sequences: A252871 A252872 A252873 * A252875 A252876 A252877

Keyword

nonn

Author

R. H. Hardin, Dec 24 2014

Status

approved