How is this different from regular combinations?

Regular combinations (C(n,r)) assume each item can only be chosen once; combinations with repetition allow choosing the same item multiple times, which increases the total count of possibilities.

Does order matter in this calculation?

No, order still doesn't matter — choosing "chocolate, chocolate, vanilla" is counted the same as "vanilla, chocolate, chocolate" — only the multiset of selections matters.

Combinations With Repetition Calculator

Calculate the number of possible combinations when choosing items from a set where repetition is allowed and order doesn't matter — for example, choosing scoops of ice cream flavors where you can pick the same flavor more than once.

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Results

Number of Combinations: 35

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Formula

C(n + r − 1, r) = (n + r − 1)! / (r! × (n − 1)!)

Learn How This Works

Number Theory and Sequences: Fibonacci, Combinations, and Basic Operations

The Fibonacci sequence, combinations with repetition, sums of consecutive integers, reciprocals, and absolute value — five foundational number theory calculations.

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