%N a(1)=1. a(n) = number of earlier terms of the sequence which are coprime to (the sum of positive integers which are <=n and missing from first (n-1) terms of sequence).
%H Diana Mecum, <a href="/A130499/b130499.txt">Table of n, a(n) for n=1,...,569</a>
%e The positive integers which are <= 9 and are missing from the first 8 terms of the sequence are 4,7,8,9. The sum of these integers is 28, so a(9) is the number of earlier terms which are coprime to 28. Therefore a(9) = 6.
%Y Cf. A130498.
%A _Leroy Quet_, May 31 2007
%E Added terms a(12) - a(569) _Diana L. Mecum_, Jan 01 2009