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 A228357 #10 Sep 08 2022 08:46:05
%S A228357 1,5,6,11,12,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,
%T A228357 36,41,42,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,
%U A228357 67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85
%N A228357 Numbers n such that sum of all primes <=n is not prime.
%H A228357 Vincenzo Librandi, <a href="/A228357/b228357.txt">Table of n, a(n) for n = 1..1000</a>
%e A228357 6 is in the sequence since 2+3+5=10 is not prime.
%t A228357 t = {}; s = 0; Do[If [PrimeQ[n], s+ = n]; If[!PrimeQ[s], AppendTo[t, n]], {n, 120}]; t
%t A228357 Position[Accumulate[Table[If[PrimeQ[n],n,0],{n,100}]],_?(!PrimeQ[ #]&)]// Flatten//Rest (* _Harvey P. Dale_, Jul 02 2018 *)
%o A228357 (Magma) [n: n in [1..120] | not IsPrime(s) where s is &+PrimesUpTo(n)];
%Y A228357 Cf. A034387, A228102.
%K A228357 nonn,easy
%O A228357 1,2
%A A228357 _Vincenzo Librandi_, Aug 21 2013