84653domain: NPropertiesPrimalityPrimeyesAppears in sequencesa(0) = 0; for n>0, a(n) is the index of the last term in A109812 that is <= 2^n - 1.at n=14A352205Indices k where k/A109812(k) reaches a new high point.at n=11A352919Prime numbersat n=8249