22299domain: NAppears in sequencesEngel series expansion (or "Egyptian product") for Catalan's constant G.at n=17A054543Semiprimes (A001358) made of nontrivial runs of identical digits.at n=26A116063Numbers k such that 4*10^k + 93 is prime.at n=23A281829Numbers with digits 2 and 9 only.at n=33A284923