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 A285485 #12 May 11 2017 11:04:10 %S A285485 0,0,2,2,0,0,44,260,0,0,33104,203712,0,0,75499696,621309008,0,0, %T A285485 492805156768,5068810602400,0,0,7346944632542720 %N A285485 Number of (n+1)-extended Skolem sequences of order n. %C A285485 Number of Rosa sequences of order n. %C A285485 a(n) computed counting reflected solutions. %H A285485 N. Francetić, E. Mendelsohn, <a href="http://dx.doi.org/10.2478/s12175-008-0110-3">A survey of Skolem-type sequences and Rosa's use of them</a>, Math. Slovaca 59 (2009), pp. 39-76 %H A285485 Jeppe Winther Larsen, <a href="https://pdfs.semanticscholar.org/6377/9c279f8e27f5ed46ff6fe5c0624eebe5de7e.pdf">Counting the Skolem sequences using inclusion-exclusion</a> %H A285485 R. Rees, N. Shalaby, A. Sharary, <a href="http://ajc.maths.uq.edu.au/pdf/21/ocr-ajc-v21-p3.pdf">Indecomposable Skolem and Rosa sequences</a> %e A285485 For n = 3, there are 2 solutions: 1 1 3 0 2 3 2 and 2 3 2 0 3 1 1. %e A285485 For n = 4, there are 2 solutions: 1 1 3 4 0 3 2 4 2 and 2 4 2 3 0 4 3 1 1. %Y A285485 Cf. A004077, A004075 %K A285485 nonn,more %O A285485 1,3 %A A285485 _Fausto A. C. Cariboni_, Apr 19 2017 %E A285485 a(1)-a(18) from Jeppe Winther Larsen (jwl(AT)itu.dk), Oct 12 2009 %E A285485 a(1)-a(18) confirmed, a(19)-a(22) from _Fausto A. C. Cariboni_, Apr 19 2017 %E A285485 a(23) from _Fausto A. C. Cariboni_, May 11 2017