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Lexicographically earliest sequence of distinct positive terms such that a(n) is a substring of a(n)*a(n+1).
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%I #15 Apr 09 2020 22:15:56

%S 1,10,11,100,21,58,51,69,39,87,33,101,1000,31,102,501,699,1001,10000,

%T 41,59,27,103,1002,5001,6999,8144,626,739,506,693,533,404,251,767,752,

%U 126,894,793,981,202,1003,10001,100000,61,92,26,151,1004,2501,7697,5037,6453,20001,59998,50001,69999

%N Lexicographically earliest sequence of distinct positive terms such that a(n) is a substring of a(n)*a(n+1).

%H Scott Shannon, <a href="/A332703/b332703.txt">Table of n, a(n) for n = 1..3656</a>

%e 1, 10, 11, 100, 21, 58, 51, 69,

%e a(1)*a(2) = 1*10 = 100 with 1 substring of 100;

%e a(2)*a(3) = 10*11 = 110 with 10 substring of 110;

%e a(3)*a(4) = 11*100 = 1100 with 11 substring of 1100;

%e a(4)*a(5) = 100*21 = 2100 with 100 substring of 2100;

%e a(5)*a(6) = 21*58 = 1218 with 21 substring of 1218;

%e a(6)*a(7) = 58*51 = 2958 with 58 substring of 2958;

%e a(7)*a(8) = 51*69 = 3519 with 51 substring of 3519; etc.

%Y Cf. A086064.

%K base,nonn

%O 1,2

%A _Eric Angelini_ and _Carole Dubois_, Feb 20 2020