a(0)=1/2, a(1)=1; a(n) = n*a(n-1) + (n-2)*a(n-2) - 2*Sum_{j=1..n-1} a(j)*a(n-j) + 2*Sum_{j=0..n-1} a(j)*a(n-1-j).
A259871
a(0)=1/2, a(1)=1; a(n) = n*a(n-1) + (n-2)*a(n-2) - 2*Sum_{j=1..n-1} a(j)*a(n-j) + 2*Sum_{j=0..n-1} a(j)*a(n-1-j).
Terms
- a(0) =1a(1) =2a(2) =5a(3) =14a(4) =45a(5) =170a(6) =777a(7) =4350a(8) =29513a(9) =236530a(10) =2179133a(11) =22576206a(12) =258821269a(13) =3245286490a(14) =44115311969a(15) =645664173566
External references
- oeis: A259871