Numbers n such that string 0,0 occurs in the base 7 representation of n but not of n-1.

Terms

a(0) =49a(1) =98a(2) =147a(3) =196a(4) =245a(5) =294a(6) =343a(7) =392a(8) =441a(9) =490a(10) =539a(11) =588a(12) =637a(13) =686a(14) =735a(15) =784a(16) =833a(17) =882a(18) =931a(19) =980a(20) =1029a(21) =1078a(22) =1127a(23) =1176a(24) =1225a(25) =1274a(26) =1323a(27) =1372a(28) =1421a(29) =1470