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arXiv 0801.1097math.CO
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Conolly数列某些关系式的组合解释

A Combinatorial Interpretation for Certain Relatives of the Conolly Sequence

B. Balamohan, Zhiqiang Li, Stephen Tanny

摘要:

对于任意整数s >= 0,我们得到了由递归(s参数化)h_s(n)= h_s(n-s- h_s(n - 1))+ h_s(n - 2 -s-h_s(n - 3)),n > s + 3生成的序列族的组合解释,初始条件h_s(1)= h_s(2)=... = h_s(s+2)= 1和h_s(s+3)= 2。我们展示了这些序列如何计算某个无限树结构的叶子数。利用这种解释,我们证明了h_s序列是“慢增长的”,即h_s序列是单调非减的,连续项增加0或1,因此每个序列命中每一个正整数。此外,对于固定的s,序列h_s(n)命中每个正整数两次,除了2的幂,所有这些都命中s+2次。我们的组合解释提供了一个简单的方法来推导这些序列的普通生成函数。

英文摘要:

For any integer s >= 0, we derive a combinatorial interpretation for the family of sequences generated by the recursion (parameterized by s) h_s(n) = h_s(n - s - h_s(n - 1)) + h_s(n - 2 - s - h_s(n - 3)), n > s + 3, with the initial conditions h_s(1) = h_s(2) = ... = h_s(s+2) = 1 and h_s(s+3) = 2. We show how these sequences count the number of leaves of a certain infinite tree structure. Using this interpretation we prove that h_s sequences are "slowly growing", that is, h_s sequences are monotone nondecreasing, with successive terms increasing by 0 or 1, so each sequence hits every positive integer. Further, for fixed s the sequence h_s(n) hits every positive integer twice except for powers of 2, all of which are hit s+2 times. Our combinatorial interpretation provides a simple approach for deriving the ordinary generating functions for these sequences.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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