Squares that become a prime number when prefixed with a 4.

Terms

a(0) =1a(1) =49a(2) =289a(3) =441a(4) =729a(5) =1521a(6) =1681a(7) =1849a(8) =2209a(9) =3481a(10) =3721a(11) =3969a(12) =5329a(13) =6889a(14) =7569a(15) =8281a(16) =8649a(17) =9409a(18) =9801a(19) =11449a(20) =13689a(21) =14641a(22) =17161a(23) =21609a(24) =25281a(25) =29241a(26) =29929a(27) =31329a(28) =36481a(29) =39601