7^a(n) is smallest power of 7 beginning with n.

Terms

a(0) =0a(1) =4a(2) =3a(3) =2a(4) =8a(5) =14a(6) =1a(7) =7a(8) =13a(9) =45a(10) =6a(11) =38a(12) =12a(13) =57a(14) =31a(15) =5a(16) =50a(17) =37a(18) =11a(19) =69a(20) =43a(21) =30a(22) =17a(23) =4a(24) =49a(25) =36a(26) =23a(27) =10a(28) =68a(29) =55