login
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
OFFSET
1,3
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 21 2009
STATUS
approved