105950

Appears in sequences

• a(n) = n*(n + 1)*(n^2 + n + 2)/4.at n=25A001621
• Coordination sequence for A_25 lattice.at n=2A035851
• z-value of the lexicographically first solution (x,y,z) of 4/n = 1/x + 1/y + 1/z with 0 < x < y < z all integers, or 0 if there is no such solution. Corresponding x and y values are in A257839 and A257840.at n=49A257841
• a(n) = (n^2 + 1)*(n^2 + 2).at n=18A304579
• Number of non-isomorphic T_0 set systems of weight n.at n=15A319559