a(n) = Sum_{i=0..2^(n-1)} binomial(2^(n-1), i)^2.
A037293
a(n) = Sum_{i=0..2^(n-1)} binomial(2^(n-1), i)^2.
Terms
- a(0) =1a(1) =2a(2) =6a(3) =70a(4) =12870a(5) =601080390
External references
- oeis: A037293
A037293
a(n) = Sum_{i=0..2^(n-1)} binomial(2^(n-1), i)^2.