A044593 Numbers n such that string 3,1 occurs in the base 8 representation of n but not of n+1.

25, 89, 153, 207, 217, 281, 345, 409, 473, 537, 601, 665, 719, 729, 793, 857, 921, 985, 1049, 1113, 1177, 1231, 1241, 1305, 1369, 1433, 1497, 1561, 1663, 1689, 1743, 1753, 1817, 1881, 1945, 2009, 2073, 2137, 2201, 2255, 2265