20920706408domain: NAppears in sequencesNumber of pairs of polynomials (f,g) in GF(3)[x] satisfying deg(f) <= n, deg(g) <= n and gcd(f,g) = 1.at n=10A087290a(0)=4, a(n) = 3*a(n-1) - 4.at n=21A115099Total number of round trips, each of length 2*n on the graph P_5 (o-o-o-o-o).at n=21A198635