%I #4 May 30 2013 13:15:44
%S 0,1,2,3,4,5,6,7,8,9,210,301,410,501,610,701,810,901,21010,30101,
%T 41010,50101,61010,70101,81010,90101,2101010,3010101,4101010,5010101,
%U 6101010,7010101,8101010,9010101,210101010,301010101,410101010,501010101
%N The sequence alternates even and odd integers but also even and odd digits; it is monotonically increasing and a(n) is always the smallest integer fitting the pattern.
%e The integer after "9" must be even, must start with an even digit and must be the smallest one larger than "9"; only "210" satisfies all requirements. The integer after "210" must be odd, must start with an odd digit and must be the smallest one larger than "210"; only "301" fits, etc.
%K base,easy,nonn
%O 0,3
%A _Eric Angelini_, Apr 27 2008
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