Project Euler Problem 445 - Retractions A (Sample Values)

Spoiler Alert! This blog entry contains content that might help you solve problem 445 of Project Euler. Please don’t read any further if you have yet to attempt to solve the problem on your own. The information is intended for those who failed to solve the problem and are looking for hints. It is posted not before the problem has a hundred solvers already.

Values for R(n)

nR(n)
11
1220
123168
12341854
123459776
1234567440
12345674416
123456785360
1234567898320

Values for ∑ R(c)

\[ \begin{equation} S(N) := \sum_{k=1}^{N-1}R\left({N \choose k} \right) \end{equation} \]

NS(N) mod 1000000007
1011118
102516982162
103853246560
104772758839
105628701600

Archived Comments

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eulerian Jan 01, 2016 00:14:55 UTC

Thanks for the post! Looks like the first set of values are actually R(n)+n (% 10^4).