Numbers n such that string 6,7 occurs in the base 9 representation of n but not of n+1.

Terms

a(0) =61a(1) =142a(2) =223a(3) =304a(4) =385a(5) =466a(6) =547a(7) =557a(8) =628a(9) =709a(10) =790a(11) =871a(12) =952a(13) =1033a(14) =1114a(15) =1195a(16) =1276a(17) =1286a(18) =1357a(19) =1438a(20) =1519a(21) =1600a(22) =1681a(23) =1762a(24) =1843a(25) =1924a(26) =2005a(27) =2015a(28) =2086a(29) =2167