%I #19 Dec 29 2022 12:11:46
%S 1,1,2,6,21,111,821,10423,236064,10375796
%N Number of distinct characteristic polynomials among all connected graphs on n nodes.
%H Travis Hoppe and Anna Petrone, <a href="https://github.com/thoppe/Encyclopedia-of-Finite-Graphs">Encyclopedia of Finite Graphs</a>
%H T. Hoppe and A. Petrone, <a href="http://arxiv.org/abs/1408.3644">Integer sequence discovery from small graphs</a>, arXiv preprint arXiv:1408.3644 [math.CO], 2014.
%H T. Hoppe and A. Petrone, <a href="http://doi.org/10.1016/j.dam.2015.07.017">Integer sequence discovery from small graphs</a>, Discr. Appl. Math. 201 (2016) 172-181.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/CharacteristicPolynomial.html">Characteristic Polynomial</a>
%Y Cf. A082104 (simple graphs, including disconnected ones, with unique characteristic polynomials).
%K nonn,hard,more
%O 1,3
%A _Travis Hoppe_ and _Anna Petrone_, Aug 05 2014
%E Terms corrected by _Eric M. Schmidt_, Mar 20 2015