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Problem 908


Problem 908


Clock Sequence II

A clock sequence is a periodic sequence of positive integers that can be broken into contiguous segments such that the sum of the n-th segment is equal to n.

For example, the sequence
1 2 3 4 3 2 1 2 3 4 3 2 1 2 3 4 3 2 1 
is a clock sequence with period 6, as it can be broken into
1|2|3|4|3 2|1 2 3|4 3|2 1 2 3|4 3 2|1 2 3 4|3 2 1 2 3|
Let C(N) be the number of different clock sequences with period at most N. For example, C(3)=3, C(4)=7 and C(10)=561.

Find C(104)mod1111211113.


钟摆序列(二)

钟摆序列是一种具有周期性的正整数序列。这种序列可以被分成连续的片段,使得第n个片段之和等于n

例如,序列
1 2 3 4 3 2 1 2 3 4 3 2 1 2 3 4 3 2 1 
是一个周期为6的钟摆序列,因为它可以被分成
1|2|3|4|3 2|1 2 3|4 3|2 1 2 3|4 3 2|1 2 3 4|3 2 1 2 3|

C(N)为周期至多为N的不同钟摆序列的数量。例如,C(3)=3C(4)=7C(10)=561

C(104)mod1111211113


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