(n-1)-st elementary symmetric function of {2, 2, 3, 3, 4, 4, 5, 5, ..., floor((n+3)/2)}.

A203153

(n-1)-st elementary symmetric function of {2, 2, 3, 3, 4, 4, 5, 5, ..., floor((n+3)/2)}.

Terms

    a(0) =1a(1) =4a(2) =16a(3) =60a(4) =276a(5) =1248a(6) =6816a(7) =36960a(8) =236160a(9) =1503360a(10) =11041920a(11) =80922240a(12) =672779520a(13) =5585448960a(14) =51894743040a(15) =481684008960

External references