Numbers n such that string 7,7 occurs in the base 8 representation of n but not of n-1.

Terms

a(0) =63a(1) =127a(2) =191a(3) =255a(4) =319a(5) =383a(6) =447a(7) =504a(8) =575a(9) =639a(10) =703a(11) =767a(12) =831a(13) =895a(14) =959a(15) =1016a(16) =1087a(17) =1151a(18) =1215a(19) =1279a(20) =1343a(21) =1407a(22) =1471a(23) =1528a(24) =1599a(25) =1663a(26) =1727a(27) =1791a(28) =1855a(29) =1919