a(1)=1; for n>1: a(n) = sum of all subsets of (a(1),..,a(n-1)).
A126391
a(1)=1; for n>1: a(n) = sum of all subsets of (a(1),..,a(n-1)).
Terms
- a(0) =1a(1) =1a(2) =4a(3) =24a(4) =240a(5) =4320a(6) =146880a(7) =9694080a(8) =1260230400a(9) =325139443200
External references
- oeis: A126391