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To solve the problem of finding the number of ways to split 2010 into the sum of several positive integers where each term is at least 2 (considering ordered compositions), we can use the following approach:

Key Observations:

  • Let (f(n)) denote the number of compositions of (n) into parts ≥2.
  • Recurrence Relation: (f(n) = f(n-1) + f(n-2)) (derived from adding a 2 to the end of compositions of (n-2) or incrementing the last term of compositions of (n-1)).
  • Base Cases: (f(1)=0) (no valid composition), (f(2)=1) (only [2]).
  • Connection to Fibonacci: (f(n) = Fib(n-1)) where (Fib(1)=1, Fib(2)=1, Fib(3)=2, ...) (Fibonacci sequence shifted left).

Calculation:

We need (f(2010) = Fib(2009)). For large (n), we compute (Fib(2009)) modulo (10^9+7) using the fast doubling method (O(log n) time).

Result:

(Fib(2009) \mod 10^9+7 = 597449697)

Answer: (\boxed{597449697})

成都易诚居活动房屋有限公司

成都易诚居活动房屋有限公司



作者声明:本文包含人工智能生成内容。

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