A044564 Numbers n such that string 6,3 occurs in the base 7 representation of n but not of n+1.

45, 94, 143, 192, 241, 290, 321, 339, 388, 437, 486, 535, 584, 633, 664, 682, 731, 780, 829, 878, 927, 976, 1007, 1025, 1074, 1123, 1172, 1221, 1270, 1319, 1350, 1368, 1417, 1466, 1515, 1564, 1613, 1662, 1693, 1711, 1760, 1809