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A166840 Number of n X 2 1..6 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, 30, 728, 5364, 24401, 84279, 242772, 614084, 1407834, 2987248, 5953244, 11262680, 20390851, 35550385, 59981016, 98327320, 157124404, 245414754 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..19.

FORMULA

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

Empirical a(n) = (16/(10)!)*n*(n-1)*(n-2)*(1486980 - 1224297*n - 103903*n^2 + 91114*n^3 + 17630*n^4 + 1342*n^5 + 53*n^6 + n^7).

Empirical G.f.: x^3*(30 + 398*x - 994*x^2 + 487*x^3 + 668*x^4 - 922*x^5 + 416*x^6 - 67*x^7)/(1 - x)^11.

Empirical E.g.f.: (16/(10)!)*x^3*(1134000 + 5745600*x + 3825360*x^2 + 799155*x^3 + 75870*x^4 + 3735*x^5 + 95*x^6 + x^7)*exp(x). (End)

EXAMPLE

All solutions for n=3

...4.3...4.3...3.1...3.1...3.1...3.1...3.2...3.2...3.2...3.2...3.1...3.1...3.2

...5.1...5.2...4.2...4.2...4.5...4.6...4.1...4.1...4.5...4.6...5.4...5.2...5.4

...6.2...6.1...5.6...6.5...6.2...5.2...5.6...6.5...6.1...5.1...6.2...6.4...6.1

------

...3.2...4.1...4.1...4.2...4.2...2.1...2.1...2.1...2.1...2.1...2.1...2.1...2.1

...5.1...5.3...5.2...5.3...5.1...3.4...3.4...3.5...3.5...3.6...3.6...4.3...4.3

...6.4...6.2...6.3...6.1...6.3...5.6...6.5...6.4...4.6...5.4...4.5...5.6...6.5

------

...2.1...2.1...2.1...2.1

...4.5...4.6...5.3...5.4

...6.3...5.3...6.4...6.3

CROSSREFS

Sequence in context: A180801 A035520 A122186 * A166828 A053509 A273435

Adjacent sequences:  A166837 A166838 A166839 * A166841 A166842 A166843

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 21 2009

STATUS

approved

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Last modified March 28 05:38 EDT 2020. Contains 333073 sequences. (Running on oeis4.)