Number of deranged matchings of 2n people with partners (of either sex) such that at least one person is matched with their spouse.

A370253

Number of deranged matchings of 2n people with partners (of either sex) such that at least one person is matched with their spouse.

Terms

    a(0) =0a(1) =1a(2) =1a(3) =7a(4) =45a(5) =401a(6) =4355a(7) =56127a(8) =836353a(9) =14144545a(10) =267629139a(11) =5601014255a(12) =128455425593

External references