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 A372519 #9 May 17 2024 05:02:08
%S A372519 0,3,5,8,12,13,17,18,20,21,24,27,28,29,32,33,37,40,41,43,44,45,48,52,
%T A372519 53,56,57,60,61,65,68,69,72,73,76,77,80,84,85,88,89,92,93,96,97,101,
%U A372519 104,105,108,109,112,113,116,117,120,124,125,126,128,129,132,133
%N A372519 Nonnegative numbers k such that 0 = Sum_{j=0..k} K(k, j) where K(k, j) is the Kronecker symbol (k / j).
%p A372519 K := (n, k) -> NumberTheory:-KroneckerSymbol(n, k):
%p A372519 isA := n -> local k; evalb(0 = add(K(n, k), k = 0..n)):
%p A372519 select(isA, [seq(0..133)]);
%o A372519 (PARI) isok(k) = sum(j=0, k, kronecker(k,j)) == 0; \\ _Michel Marcus_, May 17 2024
%Y A372519 Cf. A372728, A079896.
%K A372519 nonn
%O A372519 1,2
%A A372519 _Peter Luschny_, May 16 2024