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A290816
Number of dissections of an n-gon into polygons with odd number of sides counted up to rotations and reflections.
3
1, 1, 2, 4, 8, 23, 65, 223, 757, 2824, 10559, 40994, 160734, 641420, 2584587, 10528305, 43237978, 178974779, 745814185, 3127246179, 13185588894, 55878618492, 237905685582, 1017225981255, 4366536472758, 18812074137141, 81320795918871, 352638701880227
OFFSET
3,3
LINKS
E. Krasko, A. Omelchenko, Brown's Theorem and its Application for Enumeration of Dissections and Planar Trees, The Electronic Journal of Combinatorics, 22 (2015), #P1.17.
EXAMPLE
For a(5) = 2 the dissections of a pentagon are: a dissection into 3 triangles; a dissection into one pentagon.
MATHEMATICA
(* See A295419 for DissectionsModDihedral *)
DissectionsModDihedral[Mod[#, 2]& /@ Range[1, 31]] (* Jean-François Alcover, Sep 25 2019, after Andrew Howroyd *)
PROG
(PARI) \\ See A295419 for DissectionsModDihedral().
DissectionsModDihedral(apply(v->v%2, [1..25])) \\ Andrew Howroyd, Nov 22 2017
CROSSREFS
Cf. A049124 (counted distinctly).
Sequence in context: A018323 A151380 A295419 * A181070 A226659 A009327
KEYWORD
nonn
AUTHOR
Evgeniy Krasko, Sep 03 2017
EXTENSIONS
Terms a(16) and beyond from Andrew Howroyd, Nov 22 2017
STATUS
approved