Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #19 Mar 07 2021 03:13:36
%S 1,3,6,11,17,34,58,87,123,166,215,274,305,407,482,521,562,647,791,899,
%T 1073,1261,1327,1394,1463,1533,1677,1751,1906,1985,2067,2235,2321,
%U 2497,2681,2870,2967,3170,3273,3378,3810,3921,4034,4381,4622,4745,5001,5131,5262
%N Integers that are squarefree and also the sum of first k squarefrees for some k.
%H Amiram Eldar, <a href="/A013932/b013932.txt">Table of n, a(n) for n = 1..10000</a>
%t Select[Accumulate[Select[Range[150],SquareFreeQ]],SquareFreeQ] (* _Harvey P. Dale_, Jul 27 2011 *)
%o (PARI) lista(nn) = {my(s=0); for(k=1, nn, if(issquarefree(k)==1, s+=k; if(issquarefree(s)==1, print1(s, ", ")))); } \\ _Jinyuan Wang_, Feb 26 2020
%Y Cf. A005117, A013930, A013931, A173143.
%K nonn
%O 1,2
%A _Henri Lifchitz_
%E More terms from _Jinyuan Wang_, Feb 26 2020