A006298 -id:A006298 - cp's OEIS frontend

A269922 Triangle read by rows: T(n,f) is the number of rooted maps with n edges and f faces on an orientable surface of genus 2.

21, 483, 483, 6468, 15018, 6468, 66066, 258972, 258972, 66066, 570570, 3288327, 5554188, 3288327, 570570, 4390386, 34374186, 85421118, 85421118, 34374186, 4390386, 31039008, 313530000, 1059255456, 1558792200, 1059255456, 313530000, 31039008

Offset: 4

Gheorghe Coserea, Mar 15 2016

Row n contains n-3 terms.

			Triangle starts:
n\f  [1]        [2]        [3]        [4]        [5]        [6]
[4]  21;
[5]  483,       483;
[6]  6468,      15018,     6468;
[7]  66066,     258972,    258972,    66066;
[8]  570570,    3288327,   5554188,   3288327,   570570;
[9]  4390386,   34374186,  85421118,  85421118,  34374186,  4390386;
[10] ...

Gheorghe Coserea, Rows n = 4..204, flattened
Sean R. Carrell, Guillaume Chapuy, Simple recurrence formulas to count maps on orientable surfaces, arXiv:1402.6300 [math.CO], 2014.

Columns f=1-10 give: A006298 f=1, A288082 f=2, A288083 f=3, A288084 f=4, A288085 f=5, A288086 f=6, A288087 f=7, A288088 f=8, A288089 f=9, A288090 f=10.
Row sums give A006301 (column 2 of A269919).
Cf. A006299 (row maxima), A269921.

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}]);
Table[Q[n, f, 2], {n, 4, 10}, {f, 1, n-3}] // Flatten (* Jean-François Alcover, Aug 10 2018 *)

N = 10; G = 2; gmax(n) = min(n\2, G);
Q = matrix(N + 1, N + 1);
Qget(n, g) = { if (g < 0 || g > n/2, 0, Q[n+1, g+1]) };
Qset(n, g, v) = { Q[n+1, g+1] = v };
Quadric({x=1}) = {
  Qset(0, 0, x);
  for (n = 1, length(Q)-1, for (g = 0, gmax(n),
    my(t1 = (1+x)*(2*n-1)/3 * Qget(n-1, g),
       t2 = (2*n-3)*(2*n-2)*(2*n-1)/12 * Qget(n-2, g-1),
       t3 = 1/2 * sum(k = 1, n-1, sum(i = 0, g,
       (2*k-1) * (2*(n-k)-1) * Qget(k-1, i) * Qget(n-k-1, g-i))));
    Qset(n, g, (t1 + t2 + t3) * 6/(n+1))));
};
Quadric('x);
concat(apply(p->Vecrev(p/'x), vector(N+1 - 2*G, n, Qget(n-1 + 2*G, G))))

A035309 Triangle read by rows giving number of ways to glue sides of a 2n-gon so as to produce a surface of genus g.

Original entry on oeis.org

1, 1, 2, 1, 5, 10, 14, 70, 21, 42, 420, 483, 132, 2310, 6468, 1485, 429, 12012, 66066, 56628, 1430, 60060, 570570, 1169740, 225225, 4862, 291720, 4390386, 17454580, 12317877, 16796, 1385670, 31039008, 211083730, 351683046, 59520825, 58786, 6466460, 205633428, 2198596400, 7034538511, 4304016990

Offset: 0

Dylan Thurston

Row n contains floor((n+2)/2) terms.
a(n,g) is also the number of unicellular (i.e., 1-faced) rooted maps of genus g with n edges. #(vertices) = n - 2g + 1. Dually, this is the number of 1-vertex maps. Catalan(n)=A000108(n) divides a(n,g)2^g.
From Akhmedov and Shakirov's abstract: By pairwise gluing of sides of a polygon, one produces two-dimensional surfaces with handles and boundaries. We give the number N_{g,L}(n_1, n_2, ..., n_L) of different ways to produce a surface of given genus g with L polygonal boundaries with given numbers of sides n_1, n_2, >..., n_L. Using combinatorial relations between graphs on real two-dimensional surfaces, we derive recursive relations between N_{g,L}. We show that Harer-Zagier numbers appear as a particular case of N_{g,L} and derive a new explicit expression for them. - Jonathan Vos Post, Dec 18 2007

			Triangle starts:
n\g    [0]        [1]        [2]        [3]        [4]        [5]
[0]    1;
[1]    1;
[2]    2;         1;
[3]    5,         10;
[4]    14,        70,        21;
[5]    42,        420,       483;
[6]    132,       2310,      6468,      1485;
[7]    429,       12012,     66066,     56628;
[8]    1430,      60060,     570570,    1169740,   225225;
[9]    4862,      291720,    4390386,   17454580,  12317877;
[10]   16796,     1385670,   31039008,  211083730, 351683046, 59520825;
[11]   ...

Gheorghe Coserea, Rows n = 0..200, flattened
E. T. Akhmedov and Sh. Shakirov, Gluing of Surfaces with Polygonal Boundaries, arXiv:0712.2448 [math.CO], 2007-2008, see p. 1.
Sean R. Carrell and Guillaume Chapuy, Simple recurrence formulas to count maps on orientable surfaces, arXiv:1402.6300 [math.CO], 2014.
Ricky X. F. Chen and Christian M. Reidys, A Combinatorial Identity Concerning Plane Colored Trees and its Applications, Journal of Integer Sequences, Vol. 20 (2017), Article 17.3.7.
Benoit Collins, Ion Nechita, and Deping Ye, The absolute positive partial transpose property for random induced states, Random Matrices: Theory Appl. 01, 1250002 (2012); arXiv:1108.1935 [math-ph], 2011.
I. P. Goulden and A. Nica, A direct bijection for the Harer-Zagier formula, J. Comb. Theory, A, 111, No. 2 (2005), 224-238.
J. L. Harer and D. B. Zagier, The Euler characteristic of the moduli space of curves, Invent. Math., 85, No.3 (1986), 457-486.
S. Lando and A. Zvonkin, Graphs on surfaces and their applications, Encyclopaedia of Mathematical Sciences, 141, Springer, 2004, p. 157.
B. Lass, Démonstration combinatoire de la formule de Harer-Zagier, C. R. Acad. Sci. Paris, Serie I, 333, No.3 (2001), 155-160.
A. Mironov, A. Morozov, A. Popolitov, and Sh. Shakirov, Summing up perturbation series around superintegrable point, arXiv:2401.14392 [hep-th], 2024.
T. R. S. Walsh and A. B. Lehman, Counting rooted maps by genus, J. Comb. Theory B 13 (1972), 192-218 (Tab. 1).
Nikolai Wyderka and Andreas Ketterer, Probing the geometry of correlation matrices with randomized measurements, arXiv:2211.09610 [quant-ph], 2022.
Liang Zhao and Fengyao Yan, Note on Total Positivity for a Class of Recursive Matrices, Journal of Integer Sequences, Vol. 19 (2016), Article 16.6.5.
Jian Zhou, Hermitian One-Matrix Model and KP Hierarchy, arXiv:1809.07951 [math-ph], 2018.

Row sums give A001147(n).
Columns g=0-2 give: A000108, A002802, A006298.
The last entries in the even rows give A035319.
Cf. A270406, A270790, A270791.

a[n_, g_] := (2n)!/(n+1)!/(n-2g)! Coefficient[Series[(x/2/Tanh[x/2])^(n+1), {x, 0, n}], x, 2g]; Flatten[DeleteCases[#, 0]& /@ Table[a[n, g], {n, 0, 11}, {g, 0, n}]] (* Jean-François Alcover, Aug 30 2011, after E. T. Akhmedov & Sh. Shakirov *)

N = 10; F = 1; gmax(n) = n\2;
Q = matrix(N + 1, N + 1);
Qget(n, g) = { if (g < 0 || g > n/2, 0, Q[n+1, g+1]) };
Qset(n, g, v) = { Q[n+1, g+1] = v };
Quadric({x=1}) = {
  Qset(0, 0, x);
  for (n = 1, length(Q)-1, for (g = 0, gmax(n),
    my(t1 = (1+x)*(2*n-1)/3 * Qget(n-1, g),
       t2 = (2*n-3)*(2*n-2)*(2*n-1)/12 * Qget(n-2, g-1),
       t3 = 1/2 * sum(k = 1, n-1, sum(i = 0, g,
       (2*k-1) * (2*(n-k)-1) * Qget(k-1, i) * Qget(n-k-1, g-i))));
    Qset(n, g, (t1 + t2 + t3) * 6/(n+1))));
};
Quadric('x + O('x^(F+1)));
concat(vector(N+2-F, n, vector(1 + gmax(n-1), g, polcoeff(Qget(n+F-2, g-1), F))))
\\ Gheorghe Coserea, Mar 16 2016

Let c be the number of cycles that appear in product of a (2n)-cycle and a product of n disjoint transpositions; genus is g = (n-c+1)/2.
The Harer-Zagier formula: 1 + 2*Sum_{g>=0} Sum_{n>=2*g} a(n,g) * x^(n+1) * y^(n-2*g+1) / (2*n-1)!! = (1+x/(1-x))^y.
Equivalently, for n >= 0, Sum_{g=0..floor(n/2)} a(n,g)*y^(n-2*g+1) = (2*n-1)!! * Sum_{k=0..n} 2^k * C(n,k) * C(y,k+1).
(n+2)*a(n+1,g) = (4*n+2)*a(n,g) + (4*n^3-n)*a(n-1,g-1) for n,g > 0, a(0,0)=1 and a(0,g)=0 for g > 0.
The g.f. for column g > 0 is x^(2*g) * A270790(g) * P_g(x) / (1-4*x)^(3*g-1/2), where P_g(x) is the polynomial associated with row g of the triangle A270791. - Gheorghe Coserea, Apr 17 2016

More terms and additional comments and references from Valery A. Liskovets, Apr 13 2006

Offset corrected by Gheorghe Coserea, Mar 17 2016

A288082 a(n) is the number of rooted maps with n edges and 2 faces on an orientable surface of genus 2.

Original entry on oeis.org

483, 15018, 258972, 3288327, 34374186, 313530000, 2583699888, 19678611645, 140725699686, 955708437684, 6216591472728, 38985279745230, 236923660397172, 1401097546161936, 8089830217844928, 45732525474843801, 253705943922820830, 1383896652090932364, 7434748752218650632, 39394773780853063650

Offset: 5

Gheorghe Coserea, Jun 05 2017

nonn

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

Rooted maps of genus 2 with n edges and f faces for 1<=f<=10: A006298 f=1, this sequence, A288083 f=3, A288084 f=4, A288085 f=5, A288086 f=6, A288087 f=7, A288088 f=8, A288089 f=9, A288090 f=10.
Column 2 of A269922, column 2 of A270406.
Cf. A000108.

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) ((2 n - 1)/3 Q[n - 1, f, g] + (2 n - 1)/3 Q[n - 1, f - 1, g] + (2 n - 3) (2 n - 2) (2 n - 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] (2 k - 1) (2 l - 1) Q[k - 1, u, i] Q[l - 1, v, j], {i, 0, g}], {u, 1, f}], {k, 1, n}]);
a[n_] := Q[n, 2, 2];
Table[a[n], {n, 5, 24}] (* Jean-François Alcover, Oct 18 2018 *)

A000108_ser(N) = my(x='x+O('x^(N+1))); (1 - sqrt(1-4*x))/(2*x);
A288082_ser(N) = {
  my(y = A000108_ser(N+1));
  3*y*(y-1)^5*(7*y^4 + 294*y^3 + 309*y^2 - 547*y + 98)/(y-2)^14;
};
Vec(A288082_ser(20))

A288083 a(n) is the number of rooted maps with n edges and 3 faces on an orientable surface of genus 2.

Original entry on oeis.org

6468, 258972, 5554188, 85421118, 1059255456, 11270290416, 106853266632, 925572602058, 7454157823560, 56532447160536, 407653880116680, 2815913391715452, 18743188498056288, 120789163612555200, 756589971284883792, 4621041111902656770, 27595482540212519064, 161490751719681569736

Offset: 6

Gheorghe Coserea, Jun 05 2017

nonn

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

Rooted maps of genus 2 with n edges and f faces for 1<=f<=10: A006298 f=1, A288082 f=2, this sequence, A288084 f=4, A288085 f=5, A288086 f=6, A288087 f=7, A288088 f=8, A288089 f=9, A288090 f=10.
Column 3 of A269922, column 2 of A270407.
Cf. A000108.

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) ((2 n - 1)/3 Q[n - 1, f, g] + (2 n - 1)/3 Q[n - 1, f - 1, g] + (2 n - 3) (2 n - 2) (2 n - 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] (2 k - 1) (2 l - 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, 2];
Table[a[n], {n, 6, 23}] (* Jean-François Alcover, Oct 18 2018 *)

A000108_ser(N) = my(x='x+O('x^(N+1))); (1 - sqrt(1-4*x))/(2*x);
A288083_ser(N) = {
  my(y = A000108_ser(N+1));
  -6*y*(y-1)^6*(161*y^5 + 4005*y^4 + 4173*y^3 - 10701*y^2 + 2880*y + 560)/(y-2)^17;
};
Vec(A288083_ser(18))

A288084 a(n) is the number of rooted maps with n edges and 4 faces on an orientable surface of genus 2.

Original entry on oeis.org

66066, 3288327, 85421118, 1558792200, 22555934280, 276221817810, 2979641557620, 29079129795702, 261637840342860, 2200626948631386, 17486142956133684, 132344695964811720, 960323177351524512, 6716133365837116980, 45466867668336614472, 299027167905149145858, 1916387674555902480660

Offset: 7

Gheorghe Coserea, Jun 05 2017

nonn

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

Rooted maps of genus 2 with n edges and f faces for 1<=f<=10: A006298 f=1, A288082 f=2, A288083 f=3, this sequence, A288085 f=5, A288086 f=6, A288087 f=7, A288088 f=8, A288089 f=9, A288090 f=10.
Column 4 of A269922, column 2 of A270408.
Cf. A000108.

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) ((2 n - 1)/3 Q[n - 1, f, g] + (2 n - 1)/3 Q[n - 1, f - 1, g] + (2 n - 3) (2 n - 2) (2 n - 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] (2 k - 1) (2 l - 1) Q[k - 1, u, i] Q[l - 1, v, j], {i, 0, g}], {u, 1, f}], {k, 1, n}]);
a[n_] := Q[n, 4, 2];
Table[a[n], {n, 7, 23}] (* Jean-François Alcover, Oct 18 2018 *)

A000108_ser(N) = my(x='x+O('x^(N+1))); (1 - sqrt(1-4*x))/(2*x);
A288084_ser(N) = {
  my(y = A000108_ser(N+1));
  3*y*(y-1)^7*(9318*y^6 + 178328*y^5 + 177929*y^4 - 611583*y^3 + 195218*y^2 + 110388*y - 37576)/(y-2)^20;
};
Vec(A288084_ser(17))

A288085 a(n) is the number of rooted maps with n edges and 5 faces on an orientable surface of genus 2.

Original entry on oeis.org

570570, 34374186, 1059255456, 22555934280, 375708427812, 5235847653036, 63648856688592, 694146691745820, 6928413234959820, 64232028100704156, 559373367462490656, 4616545437250956192, 36362952155187558600, 274925536462366808760, 2004633652255211204832, 14152391716870383219492

Offset: 8

Gheorghe Coserea, Jun 05 2017

nonn

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

Rooted maps of genus 2 with n edges and f faces for 1<=f<=10: A006298 f=1, A288082 f=2, A288083 f=3, A288084 f=4, this sequence, A288086 f=6, A288087 f=7, A288088 f=8, A288089 f=9, A288090 f=10.
Column 5 of A269922, column 2 of A270409.
Cf. A000108.

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) ((2 n - 1)/3 Q[n - 1, f, g] + (2 n - 1)/3 Q[n - 1, f - 1, g] + (2 n - 3) (2 n - 2) (2 n - 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] (2 k - 1) (2 l - 1) Q[k - 1, u, i] Q[l - 1, v, j], {i, 0, g}], {u, 1, f}], {k, 1, n}]);
a[n_] := Q[n, 5, 2];
Table[a[n], {n, 8, 23}] (* Jean-François Alcover, Oct 18 2018 *)

A000108_ser(N) = my(x='x+O('x^(N+1))); (1 - sqrt(1-4*x))/(2*x);
A288085_ser(N) = {
  my(y = A000108_ser(N+1));
  -6*y*(y-1)^8*(108346*y^7 + 1760421*y^6 + 1641979*y^5 - 7296839*y^4 + 2560152*y^3 + 2713196*y^2 - 1525104*y + 132944)/(y-2)^23;
};
Vec(A288085_ser(16))

A288086 a(n) is the number of rooted maps with n edges and 6 faces on an orientable surface of genus 2.

Original entry on oeis.org

4390386, 313530000, 11270290416, 276221817810, 5235847653036, 82234427131416, 1117259292848016, 13518984452463630, 148755268498286436, 1511718920778951024, 14358354462488121408, 128656798319026864068, 1095747149735034238680, 8924653047010981590288, 69866689045523025725664

Offset: 9

Gheorghe Coserea, Jun 05 2017

nonn

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

Rooted maps of genus 2 with n edges and f faces for 1<=f<=10: A006298 f=1, A288082 f=2, A288083 f=3, A288084 f=4, A288085 f=5, this sequence, A288087 f=7, A288088 f=8, A288089 f=9, A288090 f=10.
Column 6 of A269922, column 2 of A270410.
Cf. A000108.

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) ((2 n - 1)/3 Q[n - 1, f, g] + (2 n - 1)/3 Q[n - 1, f - 1, g] + (2 n - 3) (2 n - 2) (2 n - 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] (2 k - 1) (2 l - 1) Q[k - 1, u, i] Q[l - 1, v, j], {i, 0, g}], {u, 1, f}], {k, 1, n}]);
a[n_] := Q[n, 6, 2];
Table[a[n], {n, 9, 23}] (* Jean-François Alcover, Oct 18 2018 *)

A000108_ser(N) = my(x='x+O('x^(N+1))); (1 - sqrt(1-4*x))/(2*x);
A288086_ser(N) = {
  my(y = A000108_ser(N+1));
  6*y*(y-1)^9*(2211997*y^8 + 32071458*y^7 + 27414609*y^6 - 154896511*y^5 + 58087530*y^4 + 94331624*y^3 - 68497296*y^2 + 8775424*y + 1232896)/(y-2)^26;
};
Vec(A288086_ser(15))

A288087 a(n) is the number of rooted maps with n edges and 7 faces on an orientable surface of genus 2.

Original entry on oeis.org

31039008, 2583699888, 106853266632, 2979641557620, 63648856688592, 1117259292848016, 16842445235560944, 224686278407291148, 2710382626755160416, 30044423965980553536, 309859885439753598768, 3002524783711124880936, 27551689577648333614176, 240961534103705377359840, 2019318707410947848445792

Offset: 10

Gheorghe Coserea, Jun 05 2017

nonn

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

Rooted maps of genus 2 with n edges and f faces for 1<=f<=10: A006298 f=1, A288082 f=2, A288083 f=3, A288084 f=4, A288085 f=5, A288086 f=6, this sequence, A288088 f=8, A288089 f=9, A288090 f=10.
Column 7 of A269922, column 2 of A270411.
Cf. A000108.

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) ((2 n - 1)/3 Q[n - 1, f, g] + (2 n - 1)/3 Q[n - 1, f - 1, g] + (2 n - 3) (2 n - 2) (2 n - 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] (2 k - 1) (2 l - 1) Q[k - 1, u, i] Q[l - 1, v, j], {i, 0, g}], {u, 1, f}], {k, 1, n}]);
a[n_] := Q[n, 7, 2];
Table[a[n], {n, 10, 24}] (* Jean-François Alcover, Oct 18 2018 *)

A000108_ser(N) = my(x='x+O('x^(N+1))); (1 - sqrt(1-4*x))/(2*x);
A288087_ser(N) = {
  my(y = A000108_ser(N+1));
  -12*y*(y-1)^10*(20697615*y^9 + 275716321*y^8 + 211910021*y^7 - 1514443109*y^6 + 601694224*y^5 + 1328709592*y^4 - 1136750032*y^3 + 153705072*y^2 + 76788992*y - 15442112)/(y-2)^29;
};
Vec(A288087_ser(15))

A288088 a(n) is the number of rooted maps with n edges and 8 faces on an orientable surface of genus 2.

Original entry on oeis.org

205633428, 19678611645, 925572602058, 29079129795702, 694146691745820, 13518984452463630, 224686278407291148, 3286157560248860532, 43241609165618454096, 520516978029736518606, 5805858136761540452700, 60619447491266688750132, 597358002436877437320936, 5593151345725345725640044

Offset: 11

Gheorghe Coserea, Jun 05 2017

nonn

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

Rooted maps of genus 2 with n edges and f faces for 1<=f<=10: A006298 f=1, A288082 f=2, A288083 f=3, A288084 f=4, A288085 f=5, A288086 f=6, A288087 f=7, this sequence, A288089 f=9, A288090 f=10.
Column 8 of A269922, column 2 of A270412.
Cf. A000108.

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) ((2 n - 1)/3 Q[n - 1, f, g] + (2 n - 1)/3 Q[n - 1, f - 1, g] + (2 n - 3) (2 n - 2) (2 n - 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] (2 k - 1) (2 l - 1) Q[k - 1, u, i] Q[l - 1, v, j], {i, 0, g}], {u, 1, f}], {k, 1, n}]);
a[n_] := Q[n, 8, 2];
Table[a[n], {n, 11, 24}] (* Jean-François Alcover, Oct 18 2018 *)

A000108_ser(N) = my(x='x+O('x^(N+1))); (1 - sqrt(1-4*x))/(2*x);
A288088_ser(N) = {
  my(y = A000108_ser(N+1));
  3*y*(y-1)^11*(1455480376*y^10 + 18151410348*y^9 + 12284790745*y^8 - 111454641175*y^7 + 46880062914*y^6 + 129967691724*y^5 - 125047028168*y^4 + 14650142480*y^3 + 19075464224*y^2 - 6255822912*y + 360993920)/(y-2)^32;
};
Vec(A288088_ser(14))

A288089 a(n) is the number of rooted maps with n edges and 9 faces on an orientable surface of genus 2.

Original entry on oeis.org

1293938646, 140725699686, 7454157823560, 261637840342860, 6928413234959820, 148755268498286436, 2710382626755160416, 43241609165618454096, 617910462111714896820, 8044640800289827566756, 96690983139765469347024, 1084226645505246141589704, 11439196912435362172792536, 114351801899024314438876200

Offset: 12

Gheorghe Coserea, Jun 05 2017

nonn

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

Rooted maps of genus 2 with n edges and f faces for 1<=f<=10: A006298 f=1, A288082 f=2, A288083 f=3, A288084 f=4, A288085 f=5, A288086 f=6, A288087 f=7, A288088 f=8, this sequence, A288090 f=10.
Column 9 of A269922.
Cf. A000108.

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) ((2 n - 1)/3 Q[n - 1, f, g] + (2 n - 1)/3 Q[n - 1, f - 1, g] + (2 n - 3) (2 n - 2) (2 n - 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] (2 k - 1) (2 l - 1) Q[k - 1, u, i] Q[l - 1, v, j], {i, 0, g}], {u, 1, f}], {k, 1, n}]);
a[n_] := Q[n, 9, 2];
Table[a[n], {n, 12, 25}] (* Jean-François Alcover, Oct 18 2018 *)

A000108_ser(N) = my(x='x+O('x^(N+1))); (1 - sqrt(1-4*x))/(2*x);
A288089_ser(N) = {
  my(y = A000108_ser(N+1));
  -6*y*(y-1)^12*(12205186004*y^11 + 144345246789*y^10 + 83883548039*y^9 - 978172313331*y^8 + 436600889944*y^7 + 1435650005364*y^6 - 1511798886368*y^5 + 121539026592*y^4 + 411304907520*y^3 - 171035694144*y^2 + 14120686592*y + 1573053440)/(y-2)^35;
};
Vec(A288089_ser(13))

cp's OEIS Frontend

A269922 Triangle read by rows: T(n,f) is the number of rooted maps with n edges and f faces on an orientable surface of genus 2.

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A035309 Triangle read by rows giving number of ways to glue sides of a 2n-gon so as to produce a surface of genus g.

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A288082 a(n) is the number of rooted maps with n edges and 2 faces on an orientable surface of genus 2.

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A288083 a(n) is the number of rooted maps with n edges and 3 faces on an orientable surface of genus 2.

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A288084 a(n) is the number of rooted maps with n edges and 4 faces on an orientable surface of genus 2.

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A288085 a(n) is the number of rooted maps with n edges and 5 faces on an orientable surface of genus 2.

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A288086 a(n) is the number of rooted maps with n edges and 6 faces on an orientable surface of genus 2.

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A288087 a(n) is the number of rooted maps with n edges and 7 faces on an orientable surface of genus 2.

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A288088 a(n) is the number of rooted maps with n edges and 8 faces on an orientable surface of genus 2.