Odd numbers k such that 2k-1 divides 2^k-1.

Terms

a(0) =1a(1) =763425a(2) =10888425a(3) =40068105a(4) =142086921a(5) =191345625a(6) =462784725a(7) =468545025a(8) =552451809a(9) =595018305a(10) =683993905a(11) =956917125a(12) =1013987349a(13) =1024992045a(14) =1567781325a(15) =1581567885a(16) =3094868865a(17) =3312888345a(18) =4839991545a(19) =4882263477a(20) =5064476505a(21) =5613455925a(22) =7303900125