28758601domain: NAppears in sequencesNumbers k such that 2^(2^k-2) == 1 (mod k^2) and 2^(k-1) =/= 1 (mod k).at n=6A374953Composite numbers k such that 2^(2^(k-1)-1) == 1 (mod k^2).at n=28A376253Numbers k such that 2^(2^(k-1)-1) == 1 (mod k^2) and 2^(k-1) =/= 1 (mod k).at n=2A376473