Final digit of 7^n.

Terms

a(0) =1a(1) =7a(2) =9a(3) =3a(4) =1a(5) =7a(6) =9a(7) =3a(8) =1a(9) =7a(10) =9a(11) =3a(12) =1a(13) =7a(14) =9a(15) =3a(16) =1a(17) =7a(18) =9a(19) =3a(20) =1a(21) =7a(22) =9a(23) =3a(24) =1a(25) =7a(26) =9a(27) =3a(28) =1a(29) =7