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A252824 Number of nX4 nonnegative integer arrays with upper left 0 and every value within 3 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down 1
8, 53, 340, 1920, 9075, 36292, 125892, 387849, 1082111, 2777103, 6637625, 14922949, 31813809, 64737785, 126429330, 238046837, 433778614, 767506845, 1322268502, 2223460226, 3656986483, 5893853502, 9323072932, 14495166797, 22179067861 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A252828

LINKS

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

FORMULA

Empirical: a(n) = (29/479001600)*n^12 + (29/8870400)*n^11 + (3083/43545600)*n^10 + (233/290304)*n^9 + (75539/14515200)*n^8 + (56551/2419200)*n^7 + (4051409/43545600)*n^6 + (123049/483840)*n^5 + (5473861/10886400)*n^4 + (1817149/1814400)*n^3 + (5653001/1663200)*n^2 + (23839/13860)*n + 1

EXAMPLE

Some solutions for n=4

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

..0..1..2..2....0..1..2..3....1..2..2..2....1..1..2..2....0..0..0..1

..1..2..3..3....1..2..3..3....2..2..2..2....1..2..3..3....1..1..1..2

..2..3..4..4....2..3..4..4....2..3..3..3....1..2..3..4....1..2..2..3

CROSSREFS

Sequence in context: A110099 A297334 A091870 * A054418 A293115 A337554

Adjacent sequences:  A252821 A252822 A252823 * A252825 A252826 A252827

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 22 2014

STATUS

approved

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Last modified June 22 12:56 EDT 2021. Contains 345380 sequences. (Running on oeis4.)