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%I #7 Aug 18 2019 12:28:24
%S 1,2,3,5,8,13,9,12,10,30,31,32,4,6,100,7,70,14,11,50,60,61,62,71,90,
%T 101,15,20,72,73,91,120,21,22,33,51,80,92,93,110,40,41,42,52,74,94,
%U 130,53,54,81,121,23,34,63,102,43,64,95,131,65,75,122,66,82,140,35,36,83,141,44,55,96,142,76,97,150,84,85,123,67
%N The sequence S is always extended with the smallest integer not yet present that begins with the sum of the two digits enclosing the last comma; a(1) = 1 is separated from a(2) = 2 by the first comma.
%C This sequence is conjectured to be a permutation of the integers > 0.
%H Jean-Marc Falcoz, <a href="/A309782/b309782.txt">Table of n, a(n) for n = 1..10002</a>
%e The sequence S begins with 1,2,3,5,8,13,9,12,10,30,31,32,4,...
%e The 1st comma separates the digits 1 and 2; sum is 3; a(3) = 3;
%e the 2nd comma separates the digits 2 and 3; sum is 5; a(4) = 5;
%e the 3rd comma separates the digits 3 and 5; sum is 8; a(5) = 8;
%e the 4th comma separates the digits 5 and 8; sum is 13; a(6) = 13;
%e the 5th comma separates the digits 8 and 1; sum is 9; a(7) = 9;
%e the 6th comma separates the digits 3 and 9; sum is 12; a(8) = 12;
%e the 7th comma separates the digits 9 and 1; sum is 10; a(9) = 10;
%e the 8th comma separates the digits 2 and 1; sum is 3; a(10) = 30 (as 3 is already in S);
%e the 9th comma separates the digits 0 and 3; sum is 3; a(11) = 31 (as 3 and 30 are already in S);
%e the 10th comma separates the digits 0 and 3; sum is 3; a(12) = 32 (3, 30 and 31 are already in S);
%e the 11th comma separates the digits 1 and 3; sum is 4 a(13) = 4;
%e etc.
%K nonn,base
%O 1,2
%A _Eric Angelini_ and _Jean-Marc Falcoz_, Aug 17 2019
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