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A166798 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 nondecreasing order. 0
0, 0, 105, 767, 3160, 9756, 25163, 57293, 118936, 229824, 419277, 729531, 1219856, 1971580, 3094143, 4732313, 7074704, 10363744, 14907249, 21091767, 29397864, 40417532, 54873907, 73643493, 97781096, 128547680 (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) = (n^8 + 32*n^7 + 476*n^6 + 3038*n^5 - 1141*n^4 - 35182*n^3 + 53584*n^2 - 25848*n + 5040)/5040.

From G. C. Greubel, May 26 2016: (Start)

Empirical G.f.: x^3*(x^6 + 14*x^5 - 79*x^4 + 108*x^3 + 37*x^2 - 178*x + 105 ) /(1-x)^9.

Empirical E.g.f.: (1/5040)*(5040 - 5040*x + 2520*x^2 + 87360*x^3 + 73080*x^4 + 15708*x^5 + 1414*x^6 + 60*x^7 + x^8)*exp(x) - 1. (End)

EXAMPLE

Some solutions for n=4

...1.3...2.3...1.2...1.4...1.2...1.4...1.3...1.4...2.4...1.2...1.2...1.1...1.5

...4.2...4.3...4.2...1.4...3.3...2.2...2.3...3.2...3.1...3.4...2.2...1.4...2.2

...4.5...5.1...4.3...2.3...3.3...2.3...4.4...3.2...3.3...4.4...2.3...2.2...3.4

...5.5...5.1...4.5...2.5...4.5...2.5...4.5...3.5...3.5...4.5...5.4...3.5...4.4

------

...2.3...1.4...1.2...1.4...1.5...1.1...1.1...1.3...1.2...1.2...1.2...1.2...1.1

...3.3...3.2...1.4...3.4...2.2...2.3...1.2...3.3...3.3...3.2...5.3...4.3...2.3

...4.1...3.3...3.3...3.4...3.3...4.5...4.3...4.4...3.4...4.2...5.4...5.3...3.3

...4.5...5.3...3.5...5.2...4.3...4.5...4.5...5.2...5.4...5.5...5.4...5.3...5.4

CROSSREFS

Sequence in context: A152826 A133767 A166816 * A228303 A033593 A297542

Adjacent sequences:  A166795 A166796 A166797 * A166799 A166800 A166801

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 21 2009

STATUS

approved

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Last modified December 5 00:21 EST 2021. Contains 349530 sequences. (Running on oeis4.)