38707200domain: NAppears in sequencesFixed points of iteration in A077091.at n=21A077092a(n) = Product_{k=1..n, gcd(k,n)=1} (1+k).at n=19A131553Number of closed paths of length n whose steps are 20th roots of unity, U_20(n).at n=9A198800E.g.f. A(x) satisfies A(x) = (1+x) * exp(x^3 * A(x)).at n=10A389820