login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A288273 a(n) is the number of rooted maps with n edges and 3 faces on an orientable surface of genus 4. 10
351683046, 26225260226, 993494827480, 25766235457300, 517592962672296, 8615949311310872, 123981042854132536, 1587135819804394530, 18451302662846918700, 197822824662547694148, 1979281881126113225376, 18654346303702719912848, 166862901890503876520320, 1425340713681247480547040, 11686190470805703242554960 (list; graph; refs; listen; history; text; internal format)
OFFSET

10,1

LINKS

Table of n, a(n) for n=10..24.

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

FORMULA

G.f.: -2*y*(y-1)^10*(12317877*y^9 + 793781118*y^8 + 6094043038*y^7 + 2216299748*y^6 - 23375789497*y^5 + 7963356801*y^4 + 15368481377*y^3 - 10027219339*y^2 + 877859200*y + 252711200)/(y-2)^29, where y=A000108(x).

MATHEMATICA

Q[0, 1, 0] = 1; Q[n_, f_, g_] /; n < 0 || f < 0 || g < 0 = 0;

Q[n_, f_, g_] := Q[n, f, g] = 6/(n+1) ((2n-1)/3 Q[n-1, f, g] + (2n-1)/3 Q[n - 1, f-1, g] + (2n-3) (2n-2) (2n-1)/12 Q[n-2, f, g-1] + 1/2 Sum[l = n-k; Sum[v = f-u; Sum[j = g i; Boole[l >= 1 && v >= 1 && j >= 0] (2k-1)(2l- 1) Q[k-1, u, i] Q[l-1, v, j], {i, 0, g}], {u, 1, f}], {k, 1, n}]);

a[n_] := Q[n, 3, 4];

Table[a[n], {n, 10, 24}] (* Jean-Fran├žois Alcover, Oct 16 2018 *)

CROSSREFS

Rooted maps of genus 4 with n edges and f faces for 1<=f<=10: A288271 f=1, A288272 f=2, this sequence, A288274 f=4, A288275 f=5, A288276 f=6, A288277 f=7, A288278 f=8, A288279 f=9, A288280 f=10.

Column 3 of A269924.

Cf. A000108.

Sequence in context: A257384 A186628 A032757 * A219271 A167517 A227642

Adjacent sequences:  A288270 A288271 A288272 * A288274 A288275 A288276

KEYWORD

nonn

AUTHOR

Gheorghe Coserea, Jun 08 2017

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 19 15:37 EST 2020. Contains 331049 sequences. (Running on oeis4.)