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A278773 Number of nX3 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes. 1
0, 20, 266, 1972, 10784, 48501, 189595, 665212, 2138149, 6384894, 17895624, 47447755, 119746565, 289136007, 670787381, 1500673676, 3247602855, 6817025467, 13912884597, 27665820296, 53701416899, 101922145950, 189427147850 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 3 of A278778.

LINKS

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

FORMULA

Empirical: a(n) = (1/121645100408832000)*n^19 + (1/800296713216000)*n^18 + (193/2134124568576000)*n^17 + (1/241416806400)*n^16 + (173/1280987136000)*n^15 + (26111/7846046208000)*n^14 + (12107647/188305108992000)*n^13 + (354047/362125209600)*n^12 + (113721193/9656672256000)*n^11 + (12542321/109734912000)*n^10 + (1257109487/1379524608000)*n^9 + (1427797621/241416806400)*n^8 + (1397907414289/47076277248000)*n^7 + (598789045909/5884534656000)*n^6 + (543697174847/2615348736000)*n^5 + (191422487/1005903360)*n^4 - (3436687523/44108064000)*n^3 - (46017833/154378224)*n^2 - (3115337/19399380)*n

EXAMPLE

Some solutions for n=4

..0..0..1. .0..1..0. .1..1..0. .1..1..1. .0..1..1. .1..1..1. .1..0..1

..0..0..1. .0..0..0. .0..1..0. .1..1..1. .1..0..0. .1..0..1. .1..0..0

..1..0..1. .1..0..1. .0..1..1. .0..1..0. .0..0..0. .1..1..1. .1..0..0

..0..0..1. .1..1..0. .1..1..0. .1..0..1. .1..1..1. .1..1..1. .1..1..1

CROSSREFS

Cf. A278778.

Sequence in context: A229562 A021854 A025939 * A021824 A125455 A019928

Adjacent sequences:  A278770 A278771 A278772 * A278774 A278775 A278776

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 28 2016

STATUS

approved

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Last modified April 23 18:12 EDT 2019. Contains 322387 sequences. (Running on oeis4.)