# [seqfan] Re: Two thingies with digits

franktaw at netscape.net franktaw at netscape.net
Mon Aug 15 11:08:10 CEST 2011

``` Your S is certainly not a permutation of N. In particular, it cannot contain any multiple of 10.

T probably is, but I don't see how to prove it.

-----Original Message-----
From: Eric Angelini <Eric.Angelini at kntv.be>

Hello SeqFans,

First, could someone please compute a hundred or so terms of S
where two consecutive terms of S share no digit with their sum?

This is http://oeis.org/A129562 dropping the "increasing" cons-
traint. I guess S starts:

S = 1,2,3,4,5,6,7,8,9,11,13,14,15,17,16,18,12,21...

Note that S is now a permutation of N. (Hope I didn't overlook S
in the OEIS.)

Second, could someone please also compute T, another permutation
of N, where the sum of the digits of a(n) "starts" a(n+1)?

I think that T looks like this:

T = 1,10,11,2,20,21,3,30,31,4,40,41,5,50,51,6,60,61,7,70,71,8,80,
81,9,90,91,100,12,32,52,72,92,110,22,42,...

Best,

have a nice "Ferragosto",

É.

```