Numbers k such that 25^k - 5^k - 1 is prime.

Terms

a(0) =1a(1) =2a(2) =4a(3) =15a(4) =16a(5) =24a(6) =57a(7) =206a(8) =284a(9) =1290a(10) =1722a(11) =1862a(12) =1866a(13) =3271a(14) =5306a(15) =5474a(16) =15401a(17) =18729a(18) =34757a(19) =42842a(20) =63930a(21) =89967