A360879 Number of unlabeled nonseparable (or 2-connected) loopless multigraphs with circuit rank n and degree >= 3 at each node.
0, 1, 4, 17, 118, 1198, 17133, 311757, 6803203
Offset: 1
Links
- Martin Dowd, Some results on reconstructibility of colored graphs, IJPAM, 95 (2014), 309-321. Gives the sequence up to a(8) in Figure 1.
- Martin Dowd, The source code of an implementation of the algorithm from the paper and data files containing the output graphs, 2024.
- Zhizheng Ye, Xuewen Huang, Chuanyu Wu, Xianglei Xue and Liang Sun, Synthesis of contracted graph for planar nonfractionated simple-jointed kinematic chain based on similarity information, Mechanism and Machine Theory, 181 (2023), 105227. Gives the sequence in Table 3 with an erroneous term a(8) = 311737.
Formula
a(n) = Sum_{k=2..2*n-2} A046752(n + k - 1, k).
Extensions
a(8) from the paper by Martin Dowd (2014) and a(9) from Martin Dowd (personal communication) added by Andrey Zabolotskiy, Feb 21 2024