80860

Appears in sequences

• Shifts 2 places left under Dirichlet convolution.at n=31A144366
• Expansion of (x-1)^2 / ( 1-4*x+5*x^2-4*x^3 ).at n=12A271896
• Number of 3-uniform hypergraphs on n labeled vertices where every two edges have exactly one vertex in common.at n=9A323299