a(1) = 1, a(n) = Sum_{k=1..n-1} a(k)*2^k.
A082472
a(1) = 1, a(n) = Sum_{k=1..n-1} a(k)*2^k.
Terms
- a(0) =1a(1) =2a(2) =10a(3) =90a(4) =1530a(5) =50490a(6) =3281850a(7) =423358650a(8) =108803173050
External references
- oeis: A082472
A082472
a(1) = 1, a(n) = Sum_{k=1..n-1} a(k)*2^k.