a(n) = 2nd elementary symmetric function of C(n,0), C(n,1), ..., C(n,[ n/2 ]).

A025136

a(n) = 2nd elementary symmetric function of C(n,0), C(n,1), ..., C(n,[ n/2 ]).

Terms

    a(0) =2a(1) =3a(2) =34a(3) =65a(4) =551a(5) =1190a(6) =8842a(7) =20613a(8) =141457a(9) =347930a(10) =2260567a(11) =5788458a(12) =36110426a(13) =95438348a(14) =576758282a(15) =1564082093a(16) =9212023037a(17) =25523422418a(18) =147143150689a(19) =415191345278

External references