## ::Riffle shuffle permutation

### ::concepts

In the mathematics of permutations and the study of shuffling playing cards, a **riffle shuffle permutation** is one of the permutations of a set of *n* items that can be obtained by a single riffle shuffle, in which a sorted deck of *n* cards is cut into two packets and then the two packets are interleaved (e.g. by moving cards one at a time from the bottom of one or the other of the packets to the top of the sorted deck).

As a special case of this, a (*p*,*q*)-**shuffle**, for numbers *p* and *q* with *p* + *q* = *n*, is a riffle in which the first packet has *p* cards and the second packet has *q* cards.<ref name=Weibel>Weibel, Charles (1994). *An Introduction to Homological Algebra*, p. 181. Cambridge University Press, Cambridge.</ref>

**Riffle shuffle permutation sections**

Intro Combinatorial enumeration Random distribution Permutation patterns Perfect shuffles See also References

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''n''::riffle Shuffle::''p'' ''q''::shuffles First::cards Which::number Packets::title

In the mathematics of permutations and the study of shuffling playing cards, a **riffle shuffle permutation** is one of the permutations of a set of *n* items that can be obtained by a single riffle shuffle, in which a sorted deck of *n* cards is cut into two packets and then the two packets are interleaved (e.g. by moving cards one at a time from the bottom of one or the other of the packets to the top of the sorted deck).

As a special case of this, a (*p*,*q*)-**shuffle**, for numbers *p* and *q* with *p* + *q* = *n*, is a riffle in which the first packet has *p* cards and the second packet has *q* cards.<ref name=Weibel>Weibel, Charles (1994). *An Introduction to Homological Algebra*, p. 181. Cambridge University Press, Cambridge.</ref>

**Riffle shuffle permutation sections**

Intro Combinatorial enumeration Random distribution Permutation patterns Perfect shuffles See also References

PREVIOUS: Intro | NEXT: Combinatorial enumeration |

<< | >> |