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%I #12 Nov 04 2017 01:13:07
%S 1,2,3,4,5,6,7,8,9,20,10,22,12,24,14,26,16,28,18,40,21,42,23,44,25,46,
%T 27,48,29,60,30,62,32,64,34,66,36,68,38,80,41,82,43,84,45,86,47,88,49,
%U 200,50,202,52,204,54,206,56,208,58,220,61,222,63,224,65,226,67,228,69,240,70,242,72,244,74,246,76,248,78,260,81,262,83,264,85,266,87,268
%N The pair (a(n), a(n+1)) uses only one odd digit.
%C The sequence starts with a(1) = 1 and is always extended with the smallest integer not yet used that doesn't lead to a contradiction.
%H Robert Israel, <a href="/A275775/b275775.txt">Table of n, a(n) for n = 1..10000</a>
%e The pair (1,2) uses only one odd digit (1);
%e the pair (2,3) uses only one odd digit (3);
%e the pair (3,4) uses only one odd digit (3);
%e the pair (4,5) uses only one odd digit (5);
%e the pair (5,6) uses only one odd digit (5);
%e the pair (6,7) uses only one odd digit (7);
%e the pair (7,8) uses only one odd digit (7);
%e the pair (8,9) uses only one odd digit (9);
%e the pair (9,20) uses only one odd digit (9);
%e the pair (20,10) uses only one odd digit (1);
%e the pair (10,22) uses only one odd digit (1);
%e etc.
%p a:= 0: b:= 0: Res:= NULL:
%p for i from 1 to 100 do
%p for t from a+1 while nops(select(type, convert(t,base,10),odd))<> 1 do
%p od;
%p a:= t;
%p for t from b+1 while nops(select(type,convert(t,base,10),odd))>0 do
%p od;
%p b:= t;
%p Res:= Res, a, b;
%p od:
%p Res; # _Robert Israel_, Nov 03 2017
%Y Cf. A014263 (bisection).
%K nonn,base
%O 1,2
%A _Eric Angelini_, Aug 08 2016
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