OFFSET
6,1
LINKS
Sean R. Carrell, Guillaume Chapuy, Simple recurrence formulas to count maps on orientable surfaces, arXiv:1402.6300 [math.CO], 2014.
MATHEMATICA
A000108ser[n_] := (1 - Sqrt[1 - 4*x])/(2*x) + O[x]^(n+1);
A288075ser[n_] := (y = A000108ser[n+1]; -11*y*(y-1)^6*(135*y^4 + 558*y^3 - 400*y^2 - 316*y + 158)/(y-2)^17);
Drop[CoefficientList[A288075ser[20], x], 6] (* Jean-François Alcover, Jun 13 2017, translated from PARI *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Gheorghe Coserea, Jun 07 2017
STATUS
approved