70812domain: NAppears in sequencesa(n) = A216958(n)/2.at n=18A216959Sum of the divisors of n^3 - 1.at n=31A234860G.f. A(x) satisfies: A(x) = 1 + x + x^2 + x^3 * A(x)^3.at n=17A346733a(n) = Sum_{k=0..n} (2*k+1) * binomial(2*k,k) * binomial(2*n-k,n-k).at n=6A386942