70727domain: NAppears in sequencesNumbers k such that 7*R_k - 4 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=16A099420Number of {2-1-3, 2'^e-31}-avoiding permutations of size n (see definition in the Elizalde paper).at n=12A143017a(n) = n^3 + (n+1)*(n+2).at n=41A270109