a(n) = Sum_{k=0..n} C(n^2, n*k).A167009a(n) = Sum_{k=0..n} C(n^2, n*k).Terms a(0) =1a(1) =2a(2) =8a(3) =170a(4) =16512a(5) =6643782a(6) =11582386286External referencesoeis: A167009