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 A060398 #13 Aug 15 2022 08:34:41
%S A060398 1,0,0,1,0,0,1,0,0,1,0,1,1,0,2,1,0,0,1,0,0,1,0,1,1,0,1,1,0,2,1,0,0,1,
%T A060398 0,2,1,0,0,1,0,1,1,0,2,1,0,0,1,0,4,1,0,3,1,0,1,1,0,2,1,0,0,1,0,1,1,0,
%U A060398 2,1,0,1,1,0,2,1,0,0,1,0,0,1,0,4,1,0,1,1,0,2,1,0,0,1,0,3,1,0,2,1,0,1,1,0,2
%N A060398 Values of k associated with A060397.
%H A060398 T. D. Noe, <a href="/A060398/b060398.txt">Table of n, a(n) for n = 0..10000</a>
%H A060398 Carlos Rivera, <a href="http://www.primepuzzles.net/conjectures/conj_017.htm">Conjecture 17. The Ludovicus conjecture about the Euler trinomials</a>, The Prime Puzzles & Problems Connection.
%t A060398 a[n_] := Switch[n, 0, 1, _, Module[{f, kmax0 = 2}, f[kmax_] := f[kmax] = MinimalBy[Table[{k, FactorInteger[k^2 + k + 2 n + 1][[1, 1]]}, {k, 0, kmax}], Last, 1]; f[kmax = kmax0]; f[kmax = 2 kmax]; While[f[kmax] != f[kmax/2], kmax = 2 kmax]; f[kmax][[1, 1]]]];
%t A060398 Table[a[n], {n, 0, 105}] (* _Jean-François Alcover_, Aug 15 2022 *)
%Y A060398 Cf. A060397.
%K A060398 nonn,easy
%O A060398 0,15
%A A060398 _N. J. A. Sloane_, Apr 04 2001
%E A060398 More terms from _T. D. Noe_, Mar 12 2007