274876858367domain: NAppears in sequencesPrimes of the form 4^k - 2^(k+1) - 1.at n=9A091516a(n) = (2^n-1)^2 - 2.at n=18A093112a(n) is the least prime of the form 2^m - 2^n - 1.at n=20A331217Numbers of the form (2^k-1)^2 - 2 that are squarefree.at n=16A381698