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A287047 a(n) is the number of rooted maps with n edges and 7 faces on an orientable surface of genus 1. 9
60060, 3944928, 129726760, 2908358552, 50534154408, 729734918432, 9145847808784, 102432266545800, 1046677747672360, 9908748651241088, 87930943305742512, 738178726378902064, 5905479331377981200, 45289976937922983360, 334600965220354244896, 2391127223524518889064, 16585285393291515557928 (list; graph; refs; listen; history; text; internal format)
OFFSET

8,1

LINKS

Table of n, a(n) for n=8..24.

Sean R. Carrell, Guillaume Chapuy, Simple recurrence formulas to count maps on orientable surfaces, arXiv:1402.6300 [math.CO], 2014.

PROG

(PARI)

A000108_ser(N) = my(x='x+O('x^(N+1))); (1 - sqrt(1-4*x))/(2*x);

A287047_ser(N) = {

  my(y = A000108_ser(N+1));

  -4*y*(y-1)^8*(184142*y^7 + 1083793*y^6 - 1540136*y^5 - 1481152*y^4 + 2626176*y^3 - 737232*y^2 - 184896*y + 64320)/(y-2)^23;

};

Vec(A287047_ser(17))

CROSSREFS

Rooted maps of genus 1 with n edges and f faces for 1<=f<=10: A002802(with offset 2) f=1, A006295 f=2, A006296 f=3, A288071 f=4, A288072 f=5, A287046 f=6, this sequence, A287048 f=8, A288073 f=9, A288074 f=10.

Column 7 of A269921, column 1 of A270411.

Cf. A000108.

Sequence in context: A043635 A106774 A189985 * A075671 A186556 A205983

Adjacent sequences:  A287044 A287045 A287046 * A287048 A287049 A287050

KEYWORD

nonn

AUTHOR

Gheorghe Coserea, Jun 04 2017

STATUS

approved

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Last modified April 24 04:19 EDT 2018. Contains 302984 sequences. (Running on oeis4.)