Numbers k such that both k and (k+1)/2 are Fermat pseudoprimes to base 2 (A001567).

A303531

Numbers k such that both k and (k+1)/2 are Fermat pseudoprimes to base 2 (A001567).

Terms

    a(0) =31417a(1) =130561a(2) =41541241a(3) =208969201a(4) =224074369a(5) =392099401a(6) =851934601a(7) =5186365801a(8) =33847795741a(9) =65096562721a(10) =91625968981a(11) =104070261901a(12) =111794455501a(13) =165814673473a(14) =180007280041a(15) =184020124201a(16) =276032114281a(17) =408164260141a(18) =620052300421

External references