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A166843 Number of nX3 1..4 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, 41, 476, 2733, 11045, 35848, 99847, 248101, 563888, 1192579, 2376276, 4502553 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
Table of n, a(n) for n=1..12.
FORMULA
From G. C. Greubel, May 25 2016: (Start)
Empirical: (2/9!)(n-1)*(-181440 - 22752*n + 10296*n^2 + 276752*n^3 + 197372*n^4 + 51863*n^5 + 8015*n^6 + 569*n^7 + 29*n^8),
Empirical G.f.: (1 - 10*x + 86*x^2 - 54*x^3 + 28*x^4 - 37*x^5 + 83*x^6 - 60*x^7 + 24*x^8 - 3*x^9)/(1 - x)^10.
Empirical E.g.f.: (2/9!)*(181440 - 181440*x + 3810240*x^2 + 10644480*x^3 + 8134560*x^4 + 2614248*x^5 + 420588*x^6 + 35964*x^7 + 1584*x^8 + 29*x^9)*exp(x). (End)
EXAMPLE
Some solutions for n=4
...3.2.1...4.2.2...2.1.1...2.2.1...2.2.2...2.1.1...2.2.2...3.2.1...4.2.1
...3.4.1...4.3.3...3.3.1...3.2.1...3.2.1...2.2.2...3.2.1...3.3.3...4.3.3
...3.4.4...4.4.1...4.4.1...3.4.1...3.2.1...3.4.2...3.3.3...4.3.4...4.4.4
...4.4.4...4.4.4...4.4.1...3.4.4...4.4.1...3.4.2...3.4.4...4.4.4...4.4.4
------
...4.2.1...3.3.2...2.1.1...2.1.1...2.1.1...3.2.1...3.1.1...1.1.1...3.2.2
...4.4.1...3.3.2...2.2.1...4.3.1...2.3.1...3.2.1...3.3.2...2.1.1...3.3.2
...4.4.3...4.1.2...2.3.3...4.3.1...4.4.1...3.3.1...4.4.4...4.1.1...4.4.1
...4.4.4...4.4.4...4.4.3...4.4.1...4.4.4...4.4.4...4.4.4...4.4.3...4.4.1
CROSSREFS
Sequence in context: A103735 A177491 A269087 * A098958 A269073 A086949
Adjacent sequences: A166840 A166841 A166842 * A166844 A166845 A166846
KEYWORD
nonn,more
AUTHOR
R. H. Hardin, Oct 21 2009
STATUS
approved

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Last modified August 29 23:34 EDT 2024. Contains 375520 sequences. (Running on oeis4.)