423644039001domain: NAppears in sequencesExpansion of 1/((1-3*x)*(1-9*x)).at n=12A016142a(n) = Sum_{d|n} Moebius(n/d)*d^(b-1)/phi(n) for b = 14.at n=8A161010Expansion of x^2/((3*x-1)*(3*x^2-1)).at n=26A167993