a(n) = Sum_{k=0..n} 2^(n-k) * binomial(2*n+1,k) * binomial(2*n-k-1,n-k).

A386862

a(n) = Sum_{k=0..n} 2^(n-k) * binomial(2*n+1,k) * binomial(2*n-k-1,n-k).

Terms

    a(0) =1a(1) =5a(2) =42a(3) =409a(4) =4238a(5) =45414a(6) =496996a(7) =5517929a(8) =61909878a(9) =700189606a(10) =7968994124a(11) =91158632250

External references