Stirling numbers of second kind S(2n,n).

A007820

Stirling numbers of second kind S(2n,n).

Terms

    a(0) =1a(1) =1a(2) =7a(3) =90a(4) =1701a(5) =42525a(6) =1323652a(7) =49329280a(8) =2141764053a(9) =106175395755

External references