Least positive integer k such that prime(k) + prime(k*n) is a square.

Terms

a(0) =1a(1) =10a(2) =2a(3) =1a(4) =1126a(5) =60a(6) =55a(7) =691a(8) =1a(9) =24a(10) =15a(11) =640a(12) =5a(13) =41a(14) =1a(15) =671a(16) =261a(17) =3a(18) =8a(19) =219a(20) =103a(21) =1a(22) =1843a(23) =128a(24) =2240a(25) =4a(26) =664a(27) =12a(28) =111a(29) =275