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 A283824 #7 Mar 19 2017 14:02:57 %S A283824 1,1,0,1,1,2,2,6,7,20,27,83,126 %N A283824 Number of unlabeled (and unrooted) trees on n nodes having a node that is both a center and a centroid. %C A283824 In view of the errors in the second line of the table (compare A000676 and A283823), the entries a(11)=83 and a(12)=126 should be checked carefully. %H A283824 Peter Steinbach, <a href="/A000088/a000088_17.pdf">Field Guide to Simple Graphs, Volume 1</a>, Part 17 (For Volumes 1, 2, 3, 4 of this book see A000088, A008406, A000055, A000664, respectively.) %H A283824 Peter Steinbach, <a href="/A000055/a000055_12.pdf">Field Guide to Simple Graphs, Volume 3</a>, Part 12 (For Volumes 1, 2, 3, 4 of this book see A000088, A008406, A000055, A000664, respectively.) %Y A283824 Cf. A000676, A283823, A027416. %K A283824 nonn,more %O A283824 0,6 %A A283824 _N. J. A. Sloane_, Mar 19 2017