320760domain: NAppears in sequences(n,3,4) difference families over Z_n.at n=12A011994a(n) is the sum of the divisors of Fibonacci(n) (A000045).at n=26A063477Dirichlet g.f.: Product_{k>=2} 1 / (1 - k^(-s))^(k^3).at n=35A343283