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 A307071 #19 Apr 28 2019 12:13:17
%S A307071 0,0,0,0,1,12,162,3183,74696,1892122
%N A307071 Number of simple graphs on n nodes with crossing number 1.
%e A307071 5-node: K_5.
%e A307071 6-node: includes K_{1,2,3}, K_5+K_1, (5-1)-lollipop, 2 X 3 queen, utility graph K_{3,3}.
%Y A307071 Cf. A005470 (graphs with crossing number 0).
%Y A307071 Cf. A307072 (connected graphs with crossing number 1).
%K A307071 nonn,more
%O A307071 1,6
%A A307071 _Eric W. Weisstein_, Mar 22 2019
%E A307071 a(9) from _Eric W. Weisstein_, Apr 17 2019
%E A307071 a(10) from _Eric W. Weisstein_, Apr 28 2019