This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A166800 Number of nX2 1..7 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, 0, 2016, 23485, 139417, 583175, 1954287, 5607782, 14335282, 33495930, 72818046, 149173467, 290729595, 543013497 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 LINKS FORMULA From G. C. Greubel, May 26 2016: (Start) Empirical a(n) = (32/(12)!)*(n-1)*(n-2)*(n-3)*(-2494800 - 1797300*n - 108018018n^2 + 25097225*n^3 + 12368202*n^4 + 1514529*n^5 + 93498*n^6 + 3405*n^7 + 78*n^8 + n^9). Empirical G.f.: x^4*(x^9 + 184*x^8 - 572*x^7 - 2132*x^6 + 13622*x^5 - 27732*x^4 + 26008*x^3 - 8640*x^2 - 2723*x + 2016)/(1-x)^13. (End) EXAMPLE Some solutions for n=4 ...1.7...1.7...1.4...1.4...1.5...1.6...1.2...1.3...1.5...2.2...1.7...2.3...1.7 ...2.3...2.7...3.2...3.3...1.7...2.6...3.6...1.5...2.4...4.5...3.3...6.4...3.2 ...4.5...3.4...5.5...5.2...3.2...5.3...4.6...2.7...2.6...6.3...4.5...7.1...4.4 ...4.6...6.5...6.7...7.6...4.6...7.4...5.7...6.4...3.7...7.1...6.2...7.5...5.6 ------ ...1.3...2.3...1.4...1.4...2.2...1.2...2.5...1.5...1.1...1.2...1.6...2.3...1.2 ...2.6...5.3...5.2...2.5...3.5...4.2...3.5...3.2...2.7...5.2...2.5...5.1...3.4 ...5.4...6.4...5.3...7.3...4.6...5.6...4.1...7.4...3.5...6.3...4.4...7.4...5.7 ...5.7...7.1...6.7...7.6...7.1...7.3...7.6...7.6...6.4...7.4...7.3...7.6...6.6 CROSSREFS Sequence in context: A323469 A125491 A166818 * A223216 A110851 A282331 Adjacent sequences:  A166797 A166798 A166799 * A166801 A166802 A166803 KEYWORD nonn,more AUTHOR R. H. Hardin, Oct 21 2009 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 22 14:32 EDT 2019. Contains 323480 sequences. (Running on oeis4.)