a(n) = A002105(n+1) - A005046(n), reduced tangent numbers minus the number of partitions of a 2*n-set into even blocks.

A326995

a(n) = A002105(n+1) - A005046(n), reduced tangent numbers minus the number of partitions of a 2*n-set into even blocks.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =3a(4) =117a(5) =4500a(6) =199155a(7) =10499643a(8) =663488532a(9) =50115742365

External references