[seqfan] Re: Rings of regular polygons

[Luca Petrone]

The number of configurations for rings of n-gons are the number of integer 
solution in k (number of rings) of the equation (a - 1) (1 + 2/n) + 4/n + 2/k 
== a, with a (number of sides of the n-gon inside the ring) varying from 1 to 
n/2. 

Regards, 

Luca Petrone

>----Messaggio originale----
>Da: "Andrew Weimholt" <andrew.weimholt at gmail.com>
>Data: 26/03/2017 23.59
>A: "Sequence Fanatics Discussion list"<seqfan at list.seqfan.eu>
>Ogg: [seqfan] Re: Rings of regular polygons
>
>On Sun, Mar 26, 2017 at 2:15 PM, Peter Munn <techsubs at pearceneptune.co.uk>
>wrote:
>
>>
>> If you defined it as including all those where neighbouring polygons
>> shared an edge, that is including 6 triangles around a point etc., I think
>> the sequence might be A023645, the number of divisors of n less than n/2.
>> So, I think your a(13) term should be 1.
>>
>> Peter
>>
>>
>I agree. 26 13-gons DO form a ring.
>Something is wrong with the 13-gons in the his PDF (uneven edge lengths
>perhaps).
>
>
>Andrew
>
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