

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
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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

Table of n, a(n) for n=1..70.
Eric Angelini, ab divides concatenation [ab]
E. Angelini, ab 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
Adjacent sequences: A173062 A173063 A173064 * A173066 A173067 A173068


KEYWORD

nonn,base


AUTHOR

N. J. A. Sloane, Nov 25 2010


STATUS

approved



