160220

Appears in sequences

• Expansion of 1/(1 - x^2 - x^3 - x^4) = 1/((1 + x)*(1 - x - x^3)).at n=34A013979
• Total number of edges in all connected unlabeled graphs on n nodes.at n=7A094602
• Expansion of g.f.: (1-x^2-x^3)/( (1+x)*(1-x-x^3) ).at n=38A107458
• Expansion of x*(1-x-x^2)/((1-x)*(1-x-2*x^2-x^3)).at n=18A262735