989002

Appears in sequences

• Expansion of g.f.: x*(2 - 9*x - 4*x^2)/((1 - 5*x + x^2)*(1 - 5*x - x^2)).at n=9A106804
• a(n) is the sigma irregularity of the n-th power of a path graph of length at least 3*n.at n=40A363706