43815domain: NAppears in sequencesa(0) = 1, a(1) = 1; for n>0, a(2*n) = 3*a(2n-1), a(2*n+1) = 3*a(2*n) - 2*a(n-1).at n=11A102877a(n) = (A102877(n+1) - A102877(n))/2.at n=11A111017a(n) = Sum_{d|n} sigma_3(d).at n=34A321140a(0)=0; for n > 0, a(n) = 2*a(n-1) if n-1 is prime, a(n-1) + 1 otherwise.at n=45A354973