999999999899domain: NAppears in sequencesSmallest prime of the form 10^k - prime(n), or 0 if no such prime exists.at n=25A090289Near-repdigit primes with only digits 9 and a single 8 in decimal expansion.at n=14A263431a(n) is the smallest prime q such that q + prime(n) is of form 10^k or 2*10^k, or 0 if no such prime exists.at n=25A382035