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A173065
The sequence S is to be strictly increasing, all first differences are to be distinct and not yet present in S, and a(n+1) is to be the smallest integer such that |a(n)-a(n+1)| divides the concatenation [a(n),a(n+1)].
2
1, 144, 146, 153, 156, 160, 165, 176, 184, 197, 274, 288, 294, 315, 324, 336, 352, 374, 391, 414, 432, 456, 475, 500, 510, 525, 558, 584, 612, 646, 684, 720, 740, 775, 806, 868, 912, 951, 1024, 1056, 1104, 1150, 1200, 1230, 1271, 1408, 1472, 1564, 1632, 1683, 1782, 1809, 1876, 2010, 2211, 2430, 2475, 2530, 2640, 2680, 2948, 3240, 3294, 3355, 3660, 3720, 3813, 3936, 4018, 4067
OFFSET
1,2
COMMENTS
The sequence was computed by D. S. McNeil.
See Comments by Jack Brennen in A173713.
REFERENCES
Eric Angelini, Posting to Sequence Fans Mailing List, Sep 21 2010
LINKS
E. Angelini, |a-b| divides concatenation [ab] [Cached copy, with permission]
Jack Brennen, PARI Program
EXAMPLE
Here is how we get S, starting with 1:
S = 1, 144,146,153,156,160,165,176,184,197,274,288,294,315,324,336,352,...
diffs. 143 2 7 3 4 5 11 8 13 77 14 6 21 9 12 16 22
143 is the smallest integer not yet present and dividing 1144 (=8)
2 is the smallest integer not yet present and dividing 144146 (=72073)
7 is the smallest integer not yet present and dividing 146153 (=20879)
3 is the smallest integer not yet present and dividing 153156 (=51052)
4 is the smallest integer not yet present and dividing 156160 (=39040)
5 is the smallest integer not yet present and dividing 160165 (=32033)
11 is the smallest integer not yet present and dividing 165176 (=15016)
...
CROSSREFS
Cf. A173713.
Sequence in context: A199546 A101936 A195670 * A044868 A162532 A294575
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Nov 25 2010
STATUS
approved