A044797 Numbers n such that string 8,4 occurs in the base 10 representation of n but not of n+1.

84, 184, 284, 384, 484, 584, 684, 784, 849, 884, 984, 1084, 1184, 1284, 1384, 1484, 1584, 1684, 1784, 1849, 1884, 1984, 2084, 2184, 2284, 2384, 2484, 2584, 2684, 2784, 2849, 2884, 2984, 3084, 3184, 3284, 3384, 3484, 3584