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a(n) is smallest number greater than a(n-1) such that the sequence contains a total of a(n) base 10 digits + commas through n terms (assuming one comma between each pair of terms).
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%I #4 Mar 30 2012 17:27:18

%S 1,3,5,7,9,12,15,18,21,24,27,30,33,36,39,42,45,48,51,54,57,60,63,66,

%T 69,72,75,78,81,84,87,90,93,96,99,103,107,111,115,119,123,127,131,135,

%U 139,143,147,151,155,159,163,167,171,175,179,183,187,191,195,199,203,207

%N a(n) is smallest number greater than a(n-1) such that the sequence contains a total of a(n) base 10 digits + commas through n terms (assuming one comma between each pair of terms).

%C The comma after a term is not counted as part of that term.

%e a(1)=1, the only possible initial term in base 10. a(5)=9, the smallest possible number (the other candidate is 10) such that the sequence after 5 terms would contain a(n) base 10 digits + commas.

%Y Cf. A080676.

%K base,easy,nonn

%O 1,2

%A _Matthew Vandermast_, Mar 08 2003