This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A262783 #13 Oct 13 2019 19:52:34
%S A262783 1,144,6084,33856,37636,6310144,10150596,14668900,20007729,3292234884,
%T A262783 39600602001,92437853419755481,2849708967414258609
%N A262783 Terms of A173143 (partial sums of squarefree numbers) that are square.
%C A262783 Intersection of A000290 and A173143.
%C A262783 a(12) > 10^15. - _Jon E. Schoenfield_, Oct 11 2015
%C A262783 a(14) > 3*10^21. The first 13 terms are the sums of the first 1, 21, 141, 331, 354, 4555, 5785, 6949, 8110, 104070, 360930, 551460217, 3061889301 squarefree numbers. - _Giovanni Resta_, Aug 19 2018
%e A262783 The sum of the first 14 squarefree integers is 1 + 2 + 3 + 5 + 6 + 7 + 10 + 11 + 13 + 14 + 15 + 17 + 19 + 21 = 144, a square.
%o A262783 (PARI) lista(nn) = {s = 0; i = 0; for (n=1, nn, if (issquarefree(n), i++; s += n; if (issquare(s), print1(s, ", "));););}
%Y A262783 Cf. A000290, A005117, A173143.
%K A262783 nonn,more
%O A262783 1,2
%A A262783 _Michel Marcus_, Oct 01 2015
%E A262783 a(12)-a(13) from _Giovanni Resta_, Aug 19 2018