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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

%I

%S 1,144,146,153,156,160,165,176,184,197,274,288,294,315,324,336,352,

%T 374,391,414,432,456,475,500,510,525,558,584,612,646,684,720,740,775,

%U 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

%N 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)].

%C The sequence was computed by D. S. McNeil.

%C See Comments by Jack Brennen in A173713.

%D Eric Angelini, Posting to Sequence Fans Mailing List, Sep 21 2010

%H Eric Angelini, <a href="http://www.cetteadressecomportecinquantesignes.com/DiffDivConcat.htm">|a-b| divides concatenation [ab]</a>

%H E. Angelini, <a href="/A173065/a173065.pdf">|a-b| divides concatenation [ab]</a> [Cached copy, with permission]

%H Jack Brennen, <a href="/A173713/a173713.txt">PARI Program</a>

%e Here is how we get S, starting with 1:

%e S = 1, 144,146,153,156,160,165,176,184,197,274,288,294,315,324,336,352,...

%e diffs. 143 2 7 3 4 5 11 8 13 77 14 6 21 9 12 16 22

%e 143 is the smallest integer not yet present and dividing 1144 (=8)

%e 2 is the smallest integer not yet present and dividing 144146 (=72073)

%e 7 is the smallest integer not yet present and dividing 146153 (=20879)

%e 3 is the smallest integer not yet present and dividing 153156 (=51052)

%e 4 is the smallest integer not yet present and dividing 156160 (=39040)

%e 5 is the smallest integer not yet present and dividing 160165 (=32033)

%e 11 is the smallest integer not yet present and dividing 165176 (=15016)

%e ...

%Y Cf. A173713.

%K nonn,base

%O 1,2

%A _N. J. A. Sloane_, Nov 25 2010

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Last modified September 21 06:57 EDT 2021. Contains 347596 sequences. (Running on oeis4.)