(n-1)-st elementary symmetric function of {1,1,2,2,3,3,4,4,5,5,...,Floor[(n+1)/2]}.
A203151
(n-1)-st elementary symmetric function of {1,1,2,2,3,3,4,4,5,5,...,Floor[(n+1)/2]}.
Terms
- a(0) =1a(1) =2a(2) =5a(3) =12a(4) =40a(5) =132a(6) =564a(7) =2400a(8) =12576a(9) =65760a(10) =408960a(11) =2540160a(12) =18299520a(13) =131725440a(14) =1079205120a(15) =8836853760a(16) =81157386240a(17) =745047797760
External references
- oeis: A203151