334304domain: NAppears in sequencesNumbers k such that s(k) = s(k+1) but phi(k) != phi(k+1), where s(k) = phi(k) + phi(phi(k)) + ... + 1 is the sum of iterated phi (A092693).at n=29A291177Numbers k such that k and k+1 both have an odd number of abundant divisors.at n=23A381548