Smallest prime p such that 5^n divides p^4 - 1.

Terms

a(0) =2a(1) =7a(2) =193a(3) =443a(4) =14557a(5) =14557a(6) =735443a(7) =3124999a(8) =7812499a(9) =78124999a(10) =292968749a(11) =853235443a(12) =2441406251a(13) =53834264557a(14) =122070312499a(15) =202513391693