a(n) is the number of partial bijections (or subpermutations) of an n-element set with exactly 2 fixed points.

A144087

a(n) is the number of partial bijections (or subpermutations) of an n-element set with exactly 2 fixed points.

Terms

    a(0) =0a(1) =0a(2) =1a(3) =3a(4) =24a(5) =180a(6) =1620a(7) =16380a(8) =184800a(9) =2298240a(10) =31222800a(11) =459874800a(12) =7296791040a(13) =124047443520

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