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A252926 Number of nX4 nonnegative integer arrays with upper left 0 and lower right n+4-6 and value increasing by 0 or 1 with every step right or down 1
0, 1, 33, 615, 6997, 53950, 315198, 1499394, 6083808, 21733215, 69921908, 206052448, 563440284, 1444285973, 3499040581, 8065603025, 17787652381, 37705694442, 77126966988, 152747362302, 293741640632, 549886035657 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Column 4 of A252930

LINKS

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

FORMULA

Empirical: a(n) = (13/1609445376000)*n^16 + (13/18289152000)*n^15 + (3947/149448499200)*n^14 + (20057/37362124800)*n^13 + (728009/114960384000)*n^12 + (312437/7185024000)*n^11 + (1303193/7315660800)*n^10 + (848039/1828915200)*n^9 + (11500417/20901888000)*n^8 - (1346209/373248000)*n^7 - (14478857/1149603840)*n^6 - (361673/8164800)*n^5 + (13716552599/33530112000)*n^4 + (454863863/1397088000)*n^3 - (207327073/86486400)*n^2 + (137883/80080)*n.

Empirical: G.f.: x^2*(-1 -16*x -190*x^2 -350*x^3 +1419*x^4 -3792*x^5 +7860*x^6 -11238*x^7 +11247*x^8 -8133*x^9 +4280*x^10 -1600*x^11 +401*x^12 -60*x^13+4*x^14) / (x-1)^17 . - R. J. Mathar, Nov 23 2015

EXAMPLE

Some solutions for n=4

..0..0..1..2....0..0..0..0....0..0..1..1....0..1..1..1....0..1..1..1

..0..1..1..2....0..0..0..1....1..1..1..1....0..1..1..2....1..1..1..2

..1..1..1..2....0..0..1..2....1..1..1..1....1..1..1..2....1..1..1..2

..1..1..2..2....0..0..1..2....2..2..2..2....1..1..2..2....1..1..2..2

CROSSREFS

Sequence in context: A080597 A076684 A181382 * A225970 A004328 A235894

Adjacent sequences:  A252923 A252924 A252925 * A252927 A252928 A252929

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 24 2014

STATUS

approved

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Last modified October 28 17:59 EDT 2021. Contains 348329 sequences. (Running on oeis4.)