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Triangle read by rows: number of topologies of n nested circles intersecting at most as binaries, according to number of factors.
1

%I #9 May 02 2020 07:34:03

%S 1,2,1,5,2,1,16,8,2,1,53,26,8,2,1,189,100,30,8,2,1,694,375,115,30,8,2,

%T 1,2642,1473,453,120,30,8,2,1,10270,5823,1827,473,120,30,8,2,1,40747,

%U 23479,7432,1936,479,120,30,8,2,1,164033,95618,30622,7954,1961,479,120,30,8,2,1

%N Triangle read by rows: number of topologies of n nested circles intersecting at most as binaries, according to number of factors.

%H R. J. Mathar, <a href="http://arxiv.org/abs/1603.00077">Topologically Distinct Sets of Non-intersecting Circles in the Plane</a>, arXiv:1603.00077 [math.CO], 2016.

%e Triangle begins:

%e 1,

%e 2,1,

%e 5,2,1,

%e 16,8,2,1,

%e 53,26,8,2,1,

%e 189,100,30,8,2,1,

%e 694,375,115,30,8,2,1,

%e 2642,1473,453,120,30,8,2,1,

%e 10270,5823,1827,473,120,30,8,2,1,

%e ...

%Y Row sums give A281347.

%K nonn,tabl

%O 1,2

%A _N. J. A. Sloane_, Jan 20 2017