Let be the number of undirected graphs with nodes satisfying the following properties:
- The graph is connected and has no cycles or multiple edges.
- Each node is either red, blue, or yellow.
- A red node may have no more than 4 edges connected to it.
- A blue or yellow node may have no more than 3 edges connected to it.
- An edge may not directly connect a yellow node to a yellow node.
For example, , , and .
You are also given that and .
Find .
677. 被染色的图
令 为有 个节点,且满足以下性质的无向图的个数:
- 这个图是连通的,没有重边和环。
- 每个节点只可能被染成红、蓝、黄三色之一。
- 一个红色的节点最多有 4 条边与之相连。
- 一个蓝色或黄色的节点最多有 3 条边与之相连。
- 没有一条边直接连接两个黄色节点。
已知:、、、 且 。
求 之值。
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