A044777 Numbers n such that string 6,4 occurs in the base 10 representation of n but not of n+1.

64, 164, 264, 364, 464, 564, 649, 664, 764, 864, 964, 1064, 1164, 1264, 1364, 1464, 1564, 1649, 1664, 1764, 1864, 1964, 2064, 2164, 2264, 2364, 2464, 2564, 2649, 2664, 2764, 2864, 2964, 3064, 3164, 3264, 3364, 3464, 3564