Overpseudoprimes to base 2: composite k such that k = A137576((k-1)/2).

Terms

a(0) =2047a(1) =3277a(2) =4033a(3) =8321a(4) =65281a(5) =80581a(6) =85489a(7) =88357a(8) =104653a(9) =130561a(10) =220729a(11) =253241a(12) =256999a(13) =280601a(14) =390937a(15) =458989a(16) =486737a(17) =514447a(18) =580337a(19) =818201a(20) =838861a(21) =877099a(22) =916327a(23) =976873a(24) =1016801a(25) =1082401a(26) =1145257a(27) =1194649a(28) =1207361a(29) =1251949