152415765domain: NAppears in sequencesa(0) = 0, a(n) = 10*a(n-1) + n*(n+1)*(n+2)/6.at n=9A262183a(n) = Sum_{1 <= m <= n} Sum_{1 <= k <= n+1-m} m*R(k,n+1), where R(k,b) = (b^k - 1)/(b - 1) is the base-b repunit of length k.at n=9A332082