282429536563domain: NAppears in sequencesDirichlet convolution of b_n=1 with c_n=3^(n-1).at n=24A034730a(n) = (-1)^n * [x^n] Sum_{k>=1} x^(k-1)/(1+3*x^k).at n=24A101561a(n) = Sum_{d|n} (-1)^(d-1) * 3^(n/d-1).at n=24A373276