A105957 Integers are written in the form abcd...n where "a" means "At position a in this integer there is a digit b"; "b" means: "at position b there is a digit c"; "c" means: "at position c there is a digit d"; ... and "n" means nothing.

11, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 111, 212, 222, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 322, 333, 1111, 2121, 2222, 2312, 2323, 2333, 2340, 2341, 2342, 2343, 2344, 2345, 2346, 2347, 2348, 2349, 2433, 2444, 3222, 3333, 3444, 4141, 4222