484152domain: NAppears in sequencesa(n) is the least k such that A261865(k) = A005117(n).at n=39A262036Numbers k such that k^7 - 1 and k^7 + 1 are semiprimes.at n=24A279272Inverse Weigh transform of the Fubini numbers (ordered Bell numbers, A000670).at n=7A305853