221376

Appears in sequences

• Coordination sequence for D_4 lattice.at n=24A007900
• a(n) = n^2*(2*n^2 + 1)/3.at n=24A071270
• a(n) = n^4/6 - 2*n^3/3 - n^2/6 + 5*n/3 + 1.at n=34A299198