[seqfan] Mousetrap

[Charles Greathouse]

A002467 is The game of Mousetrap with n cards (given n letters and n
envelopes, how many ways are there to fill the envelopes so that at
least one letter goes into its right envelope?).

A002468 and A002469 are named "The game of Mousetrap with n cards.".
How are these sequences defined, and how do they relate to A002467?

Charles Greathouse
Analyst/Programmer
Case Western Reserve University