Number of matchings of [2n] with no coupled arcs.

A382139

Number of matchings of [2n] with no coupled arcs.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =9a(4) =81a(5) =705a(6) =7665a(7) =100905a(8) =1524705a(9) =26022465a(10) =496042785a(11) =10445342985a(12) =240779831985

External references