77283domain: NAppears in sequencesDeficient 2-hyperperfect numbers: numbers k such that 3*k/2 + 1/2 - sigma(k) is a proper divisor of k.at n=22A305617Numbers m such that abs(K(m+1) - K(m)) = 1, where K(m) = A002034(m) is the Kempner function.at n=37A346211Numbers k such that A011776(k) = A011776(k+1).at n=19A373725