314720domain: NAppears in sequencesa(n) = Sum_{1 <= x, y <= n} lcm(x, y).at n=35A064951a(n) = (n-1)*(n+2)*(n^2 + n + 2)/4.at n=32A168566Table of coefficients of a polynomial sequence related to the Springer numbers.at n=40A185417Numbers k such that k and k+1 are both half-Zumkeller numbers (A246198).at n=26A331371