-1709

Appears in sequences

• a(n) = 1 + 3*n - 2*n^2.at n=30A168244
• Expansion of e.g.f. exp(x * (1-3*x)).at n=6A362177
• a(n) = n! * Sum_{k=0..floor(n/2)} (-n/2)^k * binomial(n-k,k)/(n-k)!.at n=6A362276