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 A243332 #27 Apr 22 2025 04:05:41
%S A243332 1,1,0,1,1,3,1,3,0,14,8,18,33,75
%N A243332 Number of simple connected graphs with n nodes that are integral and triangle-free.
%H A243332 Travis Hoppe and Anna Petrone, <a href="https://github.com/thoppe/Encyclopedia-of-Finite-Graphs">Encyclopedia of Finite Graphs</a>.
%H A243332 Travis Hoppe and Anna Petrone, <a href="http://arxiv.org/abs/1408.3644">Integer sequence discovery from small graphs</a>, arXiv:1408.3644 [math.CO], 2014.
%o A243332 (Sage) a243332 = lambda n: sum(1 for g in graphs.nauty_geng(f'-c -t {n}') if sum(m for _,m in g.charpoly().roots(ZZ))==n) # _Max Alekseyev_, Jan 31 2024
%Y A243332 Cf. A064731 (integral graphs), A024607 (triangle-free graphs).
%K A243332 nonn,more
%O A243332 1,6
%A A243332 _Travis Hoppe_ and _Anna Petrone_, Jun 03 2014
%E A243332 a(11)-a(14) from _Max Alekseyev_, Feb 02 2024