# [seqfan] Re: Digit chain

Heinz, Alois alois.heinz at hs-heilbronn.de
Thu Dec 22 12:57:35 CET 2011

```1, 10, 11, 12, 2, 20, 21, 13, 3, 23, 22, 24, 4, 14, 15, 5, 25, 26, 6,
16, 17, 7, 27, 28, 8, 18, 19, 9, 29, 32, 30, 31, 33, 34, 35, 36, 37,
38, 39, 43, 40, 41, 42, 44, 45, 46, 47, 48, 49, 54, 50, 51, 52, 53,
55, 56, 57, 58, 59, 65, 60, 61, 62, 63, 64, 66, 67, 68, 69, 76, 70,
71, 72, 73, 74, 75, 77, 78, 79, 87, 80, 81, 82, 83, 84, 85, 86, 88,
89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 109

almost the same as A107353.

Alois

Am 22.12.2011 12:33, schrieb Eric Angelini:
> Hello SeqFans,
> if S is of interest, could please someone check, extend and submit to the OEIS?
> Thanks,
> Best,
> É.
>
> -------------------------------------------------
> S = 1,10,11,12,2,20,21,13,3,23,22,24,4,14,15,5,25,...
>
> Lexicographically smallest permutation of the natural numbers such that in decimal representation a(n) shares at least one digit with a(n-1); a(1)=1.
>
> In building S, always choose the smallest term not yet present in S and not leading to a contradiction.

```