a(n) = Sum_{k=0..n} C(n,k)*2^(k*(k+1)/2).
A006898
a(n) = Sum_{k=0..n} C(n,k)*2^(k*(k+1)/2).
Terms
- a(0) =1a(1) =3a(2) =13a(3) =95a(4) =1337a(5) =38619a(6) =2310533a(7) =283841911a(8) =70927591153
External references
- oeis: A006898
A006898
a(n) = Sum_{k=0..n} C(n,k)*2^(k*(k+1)/2).