0,3

C. G. Bower, Explanation of A091057-A091062

a(n) = sum {1*s_1+2*s_2+...=n, 1*t_1+2*t_2+...=n, 1*u_1+2*u_2+...=n} (fix A[s_1, s_2, ...;t_1, t_2, ...;u_1, u_2, ...]/(1^s_1*s_1!*2^s_2*s_2!*...*1^t_1*t_1!*2^t_2*t_2!*...*1^u_1*u_1!*2^u_2*u_2!*...)) where fix A[...] = prod {i, j>=1} ( (sum {d|lcm(i, j)} (d*u_d))^(gcd(i, j)*s_i*t_j))

a(n) asymptotic to n^(n^2)/(n!^3) = A002489(n)/(A000142(n)^3)

Cf. A091057-A091062.

Sequence in context: A122911 A103235 A061463 this_sequence A155177 A054323 A061320

Adjacent sequences: A091055 A091056 A091057 this_sequence A091059 A091060 A091061

nonn

Christian G. Bower (bowerc(AT)usa.net), Dec 17 2003