72538domain: NAppears in sequencesPositive integers n such that prime(n+i) is a primitive root modulo prime(n+j) for any distinct i and j among 0, 1, 2, 3.at n=11A243839Number of (undirected) paths in the ladder graph P_2 X P_n.at n=11A288516a(n) = 36*n^2 - 8*n - 2 (n >=1).at n=44A304834