628064domain: NAppears in sequencesTriangle of coefficients of polynomials P_n(z) defined by the recursion P_0(z) = z+1; for n>=1, P_n(z) = z + Product_{k=0..n-1} P_k(z).at n=27A177701Numbers k such that k divides the sum of the first k primes with prime indices.at n=18A263541