1237518450

Appears in sequences

• a(n) = Sum_{i=0..floor(n/2)} T(i,n-i), array T as in A047072.at n=34A047074
• a(n) = (-1)^n*(2*n - 1)*CatalanNumber(n - 2) for n >= 2, a(n) = n for n = 0, 1.at n=18A078718