a(n) = (1/2)*(3rd elementary symmetric function of C(n,0), C(n,1), ..., C(n,n)).
A025132
a(n) = (1/2)*(3rd elementary symmetric function of C(n,0), C(n,1), ..., C(n,n)).
Terms
- a(0) =1a(1) =12a(2) =119a(3) =1090a(4) =9592a(5) =82432a(6) =697615a(7) =5841606a(8) =48541826a(9) =401049352a(10) =3298721384a(11) =27037279984a(12) =220976019552
External references
- oeis: A025132