885605

Appears in sequences

• a(-3) = a(-2) = a(-1) = 0, a(0) = 1, a(n) = a(n-1) + 2*a(n-2) + 2*a(n-3) + a(n-4), for n>0.at n=20A123392
• Expansion of (1 + x + x^3)/(1 - x^2 - 2*x^4 - 2*x^6 + x^8).at n=34A363958