Semiprimes of the form 2^k-k-1.

A099442

Semiprimes of the form 2^k-k-1.

Terms

    a(0) =4a(1) =26a(2) =57a(3) =247a(4) =502a(5) =4083a(6) =1073741793a(7) =4294967263a(8) =8589934558

External references