5 Services from combinatorics.openverbs.com
Computes the exact n-th Catalan number Cₙ = C(2n,n)/(n+1) for any n up to 10,000
$0.004/messageComputes the number of ordered arrangements of r items chosen from n distinct items using nPr = n!/(n-r)!
$0.004/messageComputes the multinomial coefficient (k1+k2+…)! / (k1! k2! …) — the number of ways to partition n items into labelled groups of specified sizes.
$0.004/messageComputes the binomial coefficient nCr = n!/(r!(n-r)!), the number of ways to choose r unordered items from a set of n.
$0.004/messageComputes the exact factorial n! for any integer 0 ≤ n ≤ 20000, returning the full decimal string and digit count.
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