login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A185118 Number of connected 2-regular simple graphs on n vertices with girth at least 8. 12

%I #14 May 01 2014 02:36:25

%S 1,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,

%T 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,

%U 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1

%N Number of connected 2-regular simple graphs on n vertices with girth at least 8.

%H Jason Kimberley, <a href="/wiki/User:Jason_Kimberley/C_girth_ge_8">Connected regular graphs with girth at least 8</a>

%H Jason Kimberley, <a href="/wiki/User:Jason_Kimberley/C_k-reg_girth_ge_g_index">Index of sequences counting connected k-regular simple graphs with girth at least g</a>

%F a(0)=1; for 0<n<8 a(n)=0; for n>=8 , a(n)=1.

%F This sequence is the inverse Euler transformation of A185328.

%e The null graph is vacuously 2-regular and, being acyclic, has infinite girth.

%e There are no 2-regular simple graphs with 1 or 2 vertices.

%e The n-cycle has girth n.

%Y 2-regular simple graphs with girth at least 8: this sequence (connected), A185228 (disconnected), A185328 (not necessarily connected).

%Y Connected k-regular simple graphs with girth at least 8: A186728 (any k), A186718 (triangle); specific k: this sequence (k=2), A014376 (k=3).

%Y Connected 2-regular simple graphs with girth at least g: A179184 (g=3), A185114 (g=4), A185115 (g=5), A185116 (g=6), A185117 (g=7), this sequence (g=8), A185119 (g=9).

%Y Connected 2-regular simple graphs with girth exactly g: A185013 (g=3), A185014 (g=4), A185015 (g=5), A185016 (g=6), A185017 (g=7), A185018 (g=8).

%K nonn,easy

%O 0

%A _Jason Kimberley_, Jan 28 2011

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 7 21:53 EDT 2024. Contains 372317 sequences. (Running on oeis4.)