-881543168

Appears in sequences

• a(n) = (1/2)*(1 + 3*i)^n + (1/2)*(1 - 3*i)^n where i = sqrt(-1).at n=17A120743
• a(n) = Sum_{k=0..n} (-n)^k * binomial(2*n,2*k).at n=9A333991