A166799 Number of nX2 1..6 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, 90, 1552, 9902, 41152, 133181, 364793, 885880, 1963116, 4046800, 7865858, 14559622, 25856844, 44314491, 73631219, 119053056, 187891752, 290179494

Offset

1,3

Links

Table of n, a(n) for n=1..19.

Formula

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

Empirical a(n) = (1/226800)*(n-1)*(n-2)*(n^8 + 53*n^7 + 1477*n^6 + 23435*n^5 + 173779*n^4 + 177842*n^3 - 1867077*n^2 + 450450*n - 113400).

Empirical G.f.: -x^3*(x^8 + 54*x^7 - 248*x^6 + 88*x^5 + 1261*x^4 - 2740*x^3 + 2220*x^2 - 562*x - 90)/(1-x)^11.

Empirical E.g.f.: (1/226800)*(-226800 + 226800*x - 113400*x^2 + 3439800*x^3 + 11254950*x^4 + 5751270*x^5 + 1013985*x^6 + 85050*x^7 + 3870*x^8 + 95*x^9 + x^10)*exp(x) + 1. (End)

Example

Some solutions for n=4
...1.2...1.3...1.1...2.3...1.5...1.5...1.4...1.1...1.1...1.1...1.4...2.6...2.3
...1.2...2.2...2.5...4.3...2.2...2.5...4.4...1.5...3.6...2.4...3.3...2.6...4.1
...4.6...4.2...3.4...5.3...2.3...2.6...5.3...2.3...4.6...3.6...5.2...3.1...4.1
...5.3...6.5...6.4...6.1...4.6...4.3...6.2...6.4...5.2...5.6...6.6...4.5...5.6
------
...1.3...1.1...2.4...1.2...1.1...1.4...1.2...3.6...1.6...2.2...1.4...1.5...1.2
...5.3...4.5...2.5...4.6...1.6...1.4...1.6...4.1...3.2...3.4...6.2...2.5...3.2
...5.4...6.2...3.1...5.3...2.5...3.2...4.3...4.4...4.2...3.6...6.3...4.5...5.4
...6.2...6.3...3.6...5.5...3.4...5.6...4.5...5.2...4.5...5.1...6.5...6.3...6.6

Crossrefs

Sequence in context: A250869 A234983 A166817 * A001561 A296998 A060094

Adjacent sequences: A166796 A166797 A166798 * A166800 A166801 A166802

Keyword

nonn

Author

R. H. Hardin, Oct 21 2009

Status

approved