OFFSET
1,1
COMMENTS
The primitive terms in this sequence are 11, 22, 33, 44, 55, 66, 77, 88, 99, 505, 5005, 5555, 50005, 50555, 500005, 500555, 555555, 1111116, 1111666, 1166666, 2222222, 2222277, ...; the other terms are built from the permutations of the digits of these numbers.
We find the following subsequences:
505, 5005, 50005, 500005, ..., 5000000005;
55, 5555, 555555, 55555555, ..., 5555555555.
EXAMPLE
505 is in the sequence because the digits 5,0,5 satisfy
5 = (0 + 5) mod 10;
0 = (5 + 5) mod 10;
5 = (5 + 0) mod 10.
MATHEMATICA
Select[Range[10^5], IntegerDigits[#] == Mod[Total[IntegerDigits[#]] - IntegerDigits[#], 10] &]
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Michel Lagneau, Jun 08 2013
EXTENSIONS
Edited by Jon E. Schoenfield, Sep 09 2017
STATUS
approved