-21846

Appears in sequences

• Expansion of (1-x)/(1+x+2*x^2+2*x^3).at n=29A078052
• First differences of A133730.at n=33A141416
• G.f.: x^2*(3+3*x+x^2) / ( (2*x+1) * (1+x) * (1+x+x^2) * (x^2-x+1) ) .at n=15A167617