Number of double-crossing set partitions of {1,...,n}.

A306558

Number of double-crossing set partitions of {1,...,n}.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =1a(7) =14a(8) =141a(9) =1267a(10) =10841a(11) =91091a(12) =764092

External references