a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/3)} binomial(n-1,3*k) * a(3*k) * a(n-1-3*k).
A386202
a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/3)} binomial(n-1,3*k) * a(3*k) * a(n-1-3*k).
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =6a(6) =16a(7) =52a(8) =234a(9) =1018a(10) =4724a(11) =27864a(12) =166816a(13) =1018096a(14) =7421220a(15) =56215420a(16) =427276280a(17) =3714931512a(18) =33908654224a(19) =309043657936
External references
- oeis: A386202