1443946

Appears in sequences

• Expansion of (1-x)^(-1)/(1+2*x-x^2-x^3).at n=18A077920
• a(n) = a(n-1) + 3*a(n-2) - a(n-4), with a(0)=1, a(1)=1, a(2)=4, a(3)=7.at n=18A124400