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 A235942 #17 Jan 05 2019 01:41:48 %S A235942 0,0,0,0,50,144,1078,7936,66096,611200,6248682,69926976,850848414, %T A235942 11187719984,158122436400,2390945284096,38518483536706, %U A235942 658706393035152,11918123304961222,227474585229393600,4567806759318652080 %N A235942 Number of positions (cyclic permutations) of circular permutations with exactly one (unspecified) increasing or decreasing modular 3-sequence, with clockwise and counterclockwise traversals counted as distinct. %D A235942 Paul J. Campbell, Circular permutations with exactly one modular run (3-sequence), submitted to Journal of Integer Sequences %H A235942 Wayne M. Dymáček and Isaac Lambert, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL14/Dymacek/dymacek5.html">Circular permutations avoiding runs of i, i+1, i+2 or i, i-1, i-2</a>, Journal of Integer Sequences, Vol. 14 (2011) Article 11.1.6. %F A235942 a(n) = 2*n^2 * A235937(n). %F A235942 a(n) = n^2 * A235938(n). %F A235942 a(n) = 2*n * A235939(n). %F A235942 a(n) = n * A235940(n). %F A235942 a(n) = 2 * A235941(n). %Y A235942 Cf. A165961, A165964, A165962, A078628, A078673. %Y A235942 Cf. A235937, A235938, A235939, A235940, A235941, A235943. %K A235942 nonn %O A235942 1,5 %A A235942 _Paul J. Campbell_, Jan 20 2014, with Joe Marasco and Ashish Vikram %E A235942 a(20)-a(21) from _Alois P. Heinz_, Jan 24 2014 %E A235942 Obsolete b-file deleted by _N. J. A. Sloane_, Jan 05 2019