A289655 - OEIS

%I #11 Jul 29 2017 04:19:04

%S 0,1,2,5,18,74,371,2178

%N Subset of A008989 containing one or more simple loops.

%C It appears (although it is not certain) that A268571(n) = A008989(n) - a(n).

%H Guy Valette, <a href="http://dx.doi.org/10.1007/s40598-016-0049-3">A Classification of Spherical Curves Based on Gauss Diagrams</a>, Arnold Math. J. (2016) 2:383-405, DOI 10.1007/s40598-016-0049-3.

%Y Cf. A008989, A268571.

%K nonn,more

%O 0,3

%A _N. J. A. Sloane_, Jul 17 2017