A123902 A123896 sorted and duplicates removed.

0, 1, 12, 100, 112, 121, 122, 123, 1012, 1023, 1102, 1122, 1123, 1200, 1201, 1203, 1213, 1222, 1223, 1231, 1232, 1233, 1234, 10000, 10012, 10023, 10102, 10123, 10201, 10202, 10203, 10213, 10223, 10231, 10232, 10234, 11023, 11102, 11200, 11203, 11211, 11213

Offset: 0

Author

N. J. A. Sloane, Nov 20 2006

Keywords

• nonn
• base

References

• D. E. Knuth, The Art of Computer Programming, vol. 4A, Combinatorial Algorithms, Section 7.2.1.5, p. 432, Problems 4 and 5.

Links

• R. J. Mathar, Table of n, a(n) for n = 0..4460

Programs

Mathematica

f[n_] := Block[{d = Prepend[IntegerDigits@ n, 0], a, b, w}, b = DeleteDuplicates@ d; a = Range[0, Length@ b]; w = FromDigits@ Flatten[Part[a, FirstPosition[b, #]] & /@ d]; w]; Take[Union@ Table[f[n^2], {n, 0, 320}], 42] (* Michael De Vlieger, Dec 09 2015, Version 10 *)

Extensions

More terms from Franklin T. Adams-Watters, Nov 20 2006