89756051247domain: NAppears in sequencesLerch's function q_2(n) = (2^{phi(t)} - 1)/t where t = 2*n - 1.at n=24A001226Carmichael quotients to base 2: a(n) = (2^lambda(2*n-1)-1)/(2*n-1), where lambda is the Carmichael lambda function (A002322).at n=24A329238