a(n) = 4^n mod 3^n.

Terms

a(0) =0a(1) =1a(2) =7a(3) =10a(4) =13a(5) =52a(6) =451a(7) =1075a(8) =6487a(9) =6265a(10) =44743a(11) =119923a(12) =302545a(13) =147298a(14) =589192a(15) =11922706a(16) =33341917a(17) =4227505a(18) =146050183a(19) =584200732a(20) =1174541461a(21) =4698165844a(22) =18792663376a(23) =43789593895a(24) =175158375580a(25) =700633502320