Successively better golden semiprimes.

Terms

a(0) =6a(1) =15a(2) =77a(3) =589a(4) =851a(5) =1363a(6) =15229a(7) =201563a(8) =512893a(9) =644251a(10) =1366553a(11) =3416003a(12) =7881197a(13) =377331139a(14) =400711231a(15) =2963563859a(16) =4035221017a(17) =28862500577a(18) =52027213697a(19) =133793658289a(20) =418298061641