The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A166838 Number of nX2 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. 1
 0, 4, 49, 218, 662, 1626, 3479, 6748, 12156, 20664, 33517, 52294, 78962, 115934, 166131, 233048, 320824, 434316, 579177, 761938, 990094, 1272194, 1617935, 2038260, 2545460, 3153280, 3877029, 4733694, 5742058, 6922822, 8298731, 9894704 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS R. H. Hardin, Table of n, a(n) for n=1..44 FORMULA Empirical: a(n) = (n^6 + 18*n^5 + 100*n^4 - 30*n^3 - 551*n^2 + 462*n)/180. From G. C. Greubel, May 25 2016: (Start) Empirical G.f.: x^2*(4 + 21*x - 41*x^2 + 25*x^3 - 5*x^4)/(1 - x)^7. Empirical E.g.f.: (1/180)*x^2*(360 + 1110*x + 345*x^2 + 33*x^3 + x^4)*exp(x). (End) EXAMPLE All solutions for n=3 ...1.1...1.1...1.1...1.1...1.1...1.1...1.1...1.1...1.1...2.1...2.1...2.1...2.1 ...2.1...2.1...2.2...3.1...3.2...3.2...3.2...3.3...4.2...2.1...2.1...2.2...2.2 ...3.4...4.3...4.3...4.2...3.4...4.2...4.4...4.2...4.3...3.4...4.3...3.4...4.3 ------ ...2.1...2.1...2.1...2.1...2.1...2.1...2.1...2.1...2.1...2.1...2.1...2.1...2.1 ...2.3...2.3...2.3...2.4...2.4...3.1...3.1...3.1...3.3...3.3...3.3...3.4...3.4 ...2.4...4.3...4.4...3.3...3.4...3.4...4.1...4.4...3.4...4.3...4.4...3.4...4.4 ------ ...2.1...2.1...2.1...2.2...2.2...2.2...2.2...2.2...2.2...3.1...3.1...3.1...3.1 ...4.1...4.3...4.3...3.1...3.1...3.1...3.2...3.3...4.1...3.1...3.2...3.2...3.2 ...4.3...4.3...4.4...3.4...4.1...4.4...4.1...4.1...4.3...4.2...3.4...4.2...4.4 ------ ...3.1...3.1...3.1...3.1...3.2...3.2...3.2...3.2...3.3...4.1 ...3.3...4.1...4.2...4.2...3.2...3.3...4.1...4.1...4.1...4.2 ...4.2...4.2...4.2...4.4...4.1...4.1...4.1...4.4...4.2...4.3 CROSSREFS Sequence in context: A092866 A340662 A041065 * A166826 A295535 A078187 Adjacent sequences: A166835 A166836 A166837 * A166839 A166840 A166841 KEYWORD nonn 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 14 09:16 EDT 2024. Contains 373393 sequences. (Running on oeis4.)