A043144 Numbers n such that 2 and 5 occur juxtaposed in the base 7 representation of n but not of n-1.

19, 37, 68, 86, 117, 133, 166, 184, 215, 233, 259, 282, 313, 331, 362, 380, 411, 429, 460, 476, 509, 527, 558, 576, 602, 625, 656, 674, 705, 723, 754, 772, 803, 819, 852, 870, 901, 919, 931, 999, 1017, 1048, 1066, 1097, 1115