OFFSET
1,1
COMMENTS
At each step, integers that contain duplicated digits are reduced to terms of A010784 by erasing all digits that appear more than once and bunching up the digits that remain. Leading zeros are ignored and any number that disappears entirely becomes 0. See A320486.
102735 is the smallest of 785 A010784 terms that result in a 362-term sequence, the longest possible.
LINKS
Hans Havermann, Table of n, a(n) for n = 1..362
Hans Havermann, What's so special about 102735?
EXAMPLE
2 * 102735 = [205470] => 2547
3 * 2547 = 7641
5 * 7641 = 38205
7 * 38205 = 267435
11 * 267435 = 2941785
13 * 2941785 = [38243205] => 8405
17 * 8405 = [142885] => 1425
19 * 1425 = [27075] => 205
...
2417 * 40 = [96680] => 980
2423 * 980 = [2374540] => 23750
2437 * 23750 = [57878750] => 0
CROSSREFS
KEYWORD
nonn,fini,full,base
AUTHOR
Hans Havermann, Oct 28 2018
STATUS
approved