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 A235939 #20 Jan 05 2019 01:39:17 %S A235939 0,0,0,0,5,12,77,496,3672,30560,284031,2913624,32724939,399561428, %T A235939 5270747880,74717040128,1132896574609,18297399806532,313634823814769, %U A235939 5686864630734840,108757303793301240 %N A235939 Number of circular permutations with exactly one (unspecified) increasing or decreasing modular 3-sequence, with clockwise and counterclockwise traversals not counted as distinct. %C A235939 Arrangements that differ only in the direction in which the cycle is traversed do not count as different. %D A235939 Paul J. Campbell, Circular permutations with exactly one modular run (3-sequence), submitted to Journal of Integer Sequences %H A235939 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 A235939 a(n) = n*A235937(n). %e A235939 a(5) = 5: 12354, 23415, 34521, 45132, 51243. %Y A235939 Cf. A165961, A165964, A165962, A078628, A078673. %Y A235939 Cf. A235937, A235938, A235940, A235941, A235942, A235943. %K A235939 nonn %O A235939 1,5 %A A235939 _Paul J. Campbell_, Jan 20 2014, with Joe Marasco and Ashish Vikram %E A235939 a(20)-a(21) from _Alois P. Heinz_, Jan 24 2014 %E A235939 Obsolete b-file deleted by _N. J. A. Sloane_, Jan 05 2019