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A189942 Table, read by rows, of the number of quivers of type Ã_(n-1) according to the parameter k (n >= 2, 1 <= k <= [n/2]). 0
1, 2, 5, 4, 14, 12, 42, 36, 22, 132, 108, 100, 429, 349, 315, 172, 1430, 1144, 1028, 980, 4862, 3868, 3432, 3240, 1651 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

COMMENTS

Table 1, p. 15 of Bastian.

There is a bijection with dissections of an annulus [Hermund André Torkildsen]. - N. J. A. Sloane, Jan 31 2013

REFERENCES

Francois Bergeron, Gilbert Labelle and Pierre Leroux, Combinatorial species and tree-like structures, Encyclopedia of Mathematics and its Applications, vol. 67, Cambridge University Press, Cambridge, 1998, Translated from the 1994 French original by Margaret Readdy, With a foreword by Gian-Carlo Rota.

LINKS

Table of n, a(n) for n=2..26.

Ibrahim Assem, Thomas Brustle, Gabrielle Charbonneau-Jodoin and Pierre-Guy Plamondon, Gentle algebras arising from surface triangulations, Algebra & Number Theory 4 (2010), no. 2, 201-229, arXiv:0903.3347.

Janine Bastian, Thomas Prellberg, Martin Rubey and Christian Stump, Counting the number of elements in the mutation classes of Ã_n-quivers, v3, Apr 29, 2011.

Janine Bastian, Mutation classes of Ã_n-quivers and derived equivalence classification of cluster tilted algebras of type Ã_n, Algebra Number Theory 5 (2011), no. 5, 567-594, arXiv:0901.1515.

Hermund André Torkildsen, A geometric realization of the m-cluster category of type Ã, arXiv 1208.2138. - From N. J. A. Sloane, Jan 31 2013

EXAMPLE

The table begins

===================================

n..|..r=1.|.r=2.|.r=3.|.r=4.|.r=5.|

===================================

n=2.....1

n=3.....2

n=4.....5..... 4

n=5....14.....12

n=6....42.....36....22

n=7...132....108...100

n=8...429....349...315...172

n=9..1430...1144..1028...980

n=10.4862...3868..3432..3240..1651

===================================

CROSSREFS

Sequence in context: A225046 A079053 A224272 * A251554 A002518 A093727

Adjacent sequences:  A189939 A189940 A189941 * A189943 A189944 A189945

KEYWORD

nonn,more,tabf

AUTHOR

Jonathan Vos Post, May 01 2011

STATUS

approved

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Last modified November 13 11:09 EST 2018. Contains 317133 sequences. (Running on oeis4.)