-20329

Appears in sequences

• Expansion of x*(1 - 3*x + x^2) / (1 - x - 2*x^2 + x^3).at n=19A122161
• a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) - a(n-4), n>=4; a(0) = 1, a(1) = 1, a(2) = 2, a(3) = 3.at n=28A193885