A180502 - OEIS

A180502

Triangle read by row. T(n,m) gives the number of isomorphism classes of arrangements of n pseudolines and m double pseudolines in the Moebius strip.

%I #6 Oct 07 2019 12:40:51

%S 1,1,1,1,1,1,1,5,17,59,3,45,799,15649,245351

%N Triangle read by row. T(n,m) gives the number of isomorphism classes of arrangements of n pseudolines and m double pseudolines in the Moebius strip.

%D J. Ferté, V. Pilaud and M. Pocchiola, On the number of arrangements of five double pseudolines, Abstracts 18th Fall Workshop on Comput. Geom. (FWCG08), Troy, NY, October 2008.

%H J. Ferté, V. Pilaud and M. Pocchiola, <a href="https://arxiv.org/abs/1009.1575">On the number of simple arrangements of five double pseudolines</a>, arXiv:1009.1575 [cs.CG], 2010; Discrete Comput. Geom. 45 (2011), 279-302.

%Y See A180503 for isomorphism classes of simple arrangements of n pseudolines and m double pseudolines in the Moebius strip.

%Y See A180501 for isomorphism classes of arrangements of n pseudolines and m double pseudolines in the projective plane.

%Y First diagonal gives A063854.

%K nonn,tabl,more

%O 0,8

%A _Vincent Pilaud_, Sep 08 2010