Numbers n such that string 6,7 occurs in the base 8 representation of n but not of n-1.

Terms

a(0) =55a(1) =119a(2) =183a(3) =247a(4) =311a(5) =375a(6) =439a(7) =503a(8) =567a(9) =631a(10) =695a(11) =759a(12) =823a(13) =887a(14) =951a(15) =1015a(16) =1079a(17) =1143a(18) =1207a(19) =1271a(20) =1335a(21) =1399a(22) =1463a(23) =1527a(24) =1591a(25) =1655a(26) =1719a(27) =1783a(28) =1847a(29) =1911