A292623 Number of median graphs on n nodes.
1, 1, 1, 3, 4, 11, 23, 69, 178, 567, 1741, 5890, 20005, 71294, 257889, 958595
Offset: 1
Examples
n = 1: singleton graph K_1 (1 graph)
n = 2: P_2 = K_2 (1 graph)
n = 3: P_3 (1 graph)
n = 4: K_{1,3}, P_4, square graph P_2 X P_2 (3 graphs)
n = 5: banner graph, fork graph, P_5, S_5 = K_{1,4} (4 graphs)
Here, X denotes the graph Cartesian product
Links
- Eric Weisstein's World of Mathematics, Median Graph
Extensions
a(11)-a(16) from Brendan McKay, Apr 15 2019