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A166839 Number of nX2 1..5 arrays containing at least one of each value, all equal values connected, rows considered as a single number in nondecreasing order, and columns considered as a single number in decreasing order. 0
0, 0, 55, 478, 2166, 7120, 19219, 45316, 96732, 191232, 355575, 628738, 1065922, 1743456, 2764723, 4267240, 6431032, 9488448, 13735575, 19545414, 27382990, 37822576, 51567219, 69470764, 92562580, 122075200 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..26.

FORMULA

Empirical: a(n) = (1/7!)*n*(n-1)*(n-2)*(n^5 + 35*n^4 + 523*n^3 + 3361*n^2 + 4396*n - 14436).

From G. C. Greubel, May 25 2016: (Start)

Empirical G.f.: x^3*(55 - 17*x - 156*x^2 + 214*x^3 - 107*x^4 + 19*x^5)/(1 - x)^9.

Empirical E.g.f.: (1/7!)*x^3*(46200 + 54180*x + 13692*x^2 + 1358*x^3 + 60*x^4 + x^5)*exp(x). (End)

EXAMPLE

Some solutions for n=4

...3.2...3.2...3.2...2.1...2.1...3.1...2.1...3.1...2.1...2.1...2.2...1.1...2.2

...4.2...3.5...5.1...3.1...2.1...3.2...4.1...3.2...2.3...2.2...4.1...2.1...3.2

...5.1...4.1...5.4...4.5...3.4...3.4...5.3...3.3...5.4...3.4...5.3...2.4...4.2

...5.5...4.4...5.4...4.5...5.4...5.4...5.3...5.4...5.5...5.4...5.3...5.3...5.1

------

...2.2...1.1...3.1...2.1...4.3...4.2...1.1...2.2...3.2...3.2...4.1...1.1...2.1

...3.1...2.1...3.1...3.3...5.1...4.3...3.1...2.2...4.2...3.2...4.1...3.1...2.2

...4.1...3.4...3.5...3.4...5.2...4.4...4.4...3.1...4.2...3.4...4.3...4.2...2.4

...4.5...5.4...4.2...3.5...5.5...5.1...5.2...4.5...5.1...5.1...5.2...4.5...5.3

CROSSREFS

Sequence in context: A129217 A116060 A145054 * A166827 A266035 A241699

Adjacent sequences:  A166836 A166837 A166838 * A166840 A166841 A166842

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 21 2009

STATUS

approved

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Last modified June 29 23:00 EDT 2022. Contains 354913 sequences. (Running on oeis4.)