%I A020644
%S A020644 1,4,18,53,134,154,170,319,348,373,400,460,522,552,588,661,741,858,899,
%T A020644 985,1033,1081,1275,1324,1375,1769,1829,1949,2143,2276,2475,2687,2988,
%U A020644 3063,3222,3304,3384,3466,3553,3636,3724,3994,4085,4469,4561,4663,5055
%N A020644 a(n)-th non-square-free is sum of first k non-square-frees for some k.
%Y A020644 Cf. A013933, A013934, A013935.
%Y A020644 Sequence in context: A092349 A027659 A059133 this_sequence A027286 A119044 
               A058851
%Y A020644 Adjacent sequences: A020641 A020642 A020643 this_sequence A020645 A020646 
               A020647
%K A020644 nonn
%O A020644 1,2
%A A020644 N. J. A. Sloane (njas(AT)research.att.com), Renaud Lifchitz (100637.64(AT)CompuServe.COM), 
               David W. Wilson (davidwwilson(AT)comcast.net)