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 A003443 Number of nonequivalent dissections of an n-gon into n-4 polygons by nonintersecting diagonals rooted at a cell up to rotation. (Formerly M3104) 3
 1, 3, 24, 150, 825, 4205, 20384, 95472, 436050, 1954150, 8629528, 37665030, 162845865, 698599125, 2977488000, 12620579140, 53243068230, 223707978090, 936619554000, 3909283969500, 16272003594658, 67565854800378, 279942274434624 (list; graph; refs; listen; history; text; internal format)
 OFFSET 5,2 COMMENTS Number of dissections of regular n-gon into n-4 polygons without reflection and rooted at a cell. - Sean A. Irvine, May 05 2015 The conditions imposed mean that the dissection will always be composed of either 1 pentagon and n-5 triangles or 2 quadrilaterals and n-6 triangles. - Andrew Howroyd, Nov 23 2017 REFERENCES N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS Andrew Howroyd, Table of n, a(n) for n = 5..200 P. Lisonek, Closed forms for the number of polygon dissections, Journal of Symbolic Computation 20 (1995), 595-601. C. R. Read, On general dissections of a polygon, Aequat. math. 18 (1978) 370-388. PROG (PARI) \\ See A003442 for DissectionsModCyclicRooted() { my(v=DissectionsModCyclicRooted(apply(i->if(i>=3&&i<=5, y^(i-3) + O(y^3)), [1..30]))); apply(p->polcoeff(p, 2), v[5..#v]) } \\ Andrew Howroyd, Nov 22 2017 CROSSREFS Cf. A003442, A003454. Sequence in context: A226511 A125651 A043017 * A119581 A240916 A006292 Adjacent sequences:  A003440 A003441 A003442 * A003444 A003445 A003446 KEYWORD nonn AUTHOR EXTENSIONS More terms from Sean A. Irvine, May 05 2015 Name clarified and offset changed by Andrew Howroyd, Nov 22 2017 STATUS approved

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Last modified February 16 16:00 EST 2020. Contains 331961 sequences. (Running on oeis4.)