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A166808 Number of n X 5 1..2 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. 1
4, 19, 54, 124, 250, 460, 790, 1285, 2000, 3001, 4366, 6186, 8566, 11626, 15502, 20347, 26332, 33647, 42502, 53128, 65778, 80728, 98278, 118753, 142504, 169909, 201374, 237334, 278254, 324630, 376990, 435895, 501940, 575755, 658006, 749396, 850666, 962596 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1000

FORMULA

a(n) = binomial(n+5,5) - 2. - Jeffrey Shallit, May 30 2012

From G. C. Greubel, May 24 2016: (Start)

G.f.: 1/(1-x)^6 - (1+x)/(1-x).

E.g.f.: (1/5!)*(x^5 + 25*x^4 + 200*x^3 + 600*x^2 + 600*x -120)*exp(x) +1. (End)

EXAMPLE

Some solutions for n=4

...1.1.1.1.1...1.1.1.1.1...1.1.1.1.1...1.1.1.1.1...1.1.1.1.2...1.1.1.1.2

...1.1.1.1.1...1.1.1.1.1...1.1.1.1.2...1.1.1.2.2...1.1.1.2.2...1.1.1.1.2

...1.1.2.2.2...1.1.1.2.2...1.1.1.2.2...2.2.2.2.2...1.1.2.2.2...1.1.1.2.2

...1.1.2.2.2...2.2.2.2.2...1.1.2.2.2...2.2.2.2.2...1.1.2.2.2...1.1.1.2.2

------

...1.1.1.1.1...1.1.1.1.2...1.1.1.2.2...1.1.1.2.2...1.2.2.2.2...1.1.1.2.2

...1.1.1.2.2...1.1.1.1.2...1.1.2.2.2...2.2.2.2.2...1.2.2.2.2...1.1.1.2.2

...1.1.1.2.2...2.2.2.2.2...1.1.2.2.2...2.2.2.2.2...2.2.2.2.2...2.2.2.2.2

...2.2.2.2.2...2.2.2.2.2...1.1.2.2.2...2.2.2.2.2...2.2.2.2.2...2.2.2.2.2

MATHEMATICA

Table[Binomial[n+5, 5] -2, {n, 1, 100}] (* G. C. Greubel, May 24 2016 *)

CROSSREFS

Sequence in context: A304993 A171354 A159833 * A253008 A186310 A122684

Adjacent sequences:  A166805 A166806 A166807 * A166809 A166810 A166811

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 21 2009

STATUS

approved

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Last modified October 21 14:30 EDT 2019. Contains 328301 sequences. (Running on oeis4.)