1400523domain: NAppears in sequencesNumbers n such that pi(n) = P(d_1!!)*P(d_2!!)*...*P(d_k!!) where d_1 d_2 ... d_k is the decimal expansion of n and P(i) is i-th prime.at n=4A098684Expansion of Product_{k>=2} 1/(1 - k*x^k).at n=26A317912