20954domain: NAppears in sequencesNumbers k such that the continued fraction for sqrt(k) has period 53.at n=29A020392Molecular topological indices of the path graphs P_n.at n=31A121318Where records occur in A144294.at n=8A144295Number of positive solutions to (x_1)^2 + (x_2)^2 + (x_3)^2 + (x_4)^2 <= n^2.at n=15A341423