Numbers n such that string 6,4 occurs in the base 10 representation of n but not of n+1.

Terms

a(0) =64a(1) =164a(2) =264a(3) =364a(4) =464a(5) =564a(6) =649a(7) =664a(8) =764a(9) =864a(10) =964a(11) =1064a(12) =1164a(13) =1264a(14) =1364a(15) =1464a(16) =1564a(17) =1649a(18) =1664a(19) =1764a(20) =1864a(21) =1964a(22) =2064a(23) =2164a(24) =2264a(25) =2364a(26) =2464a(27) =2564a(28) =2649a(29) =2664