A269924
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 4.
Original entry on oeis.org
225225, 12317877, 12317877, 351683046, 792534015, 351683046, 7034538511, 26225260226, 26225260226, 7034538511, 111159740692, 600398249550, 993494827480, 600398249550, 111159740692, 1480593013900, 10743797911132, 25766235457300, 25766235457300, 10743797911132, 1480593013900, 17302190625720, 160576594766588, 517592962672296, 750260619502310, 517592962672296, 160576594766588, 17302190625720
Offset: 8
Triangle starts:
n\f [1] [2] [3] [4]
[8] 225225;
[9] 12317877, 12317877;
[10] 351683046, 792534015, 351683046;
[11] 7034538511, 26225260226, 26225260226, 7034538511;
[12] ...
Cf.
A035309,
A269921,
A269922,
A269923,
A269925,
A270406,
A270407,
A270408,
A270409,
A270410,
A270412.
-
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, 4], {n, 8, 14}, {f, 1, n-7}] // Flatten (* Jean-François Alcover, Aug 10 2018 *)
-
N = 14; G = 4; 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))))
A269925
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 5.
Original entry on oeis.org
59520825, 4304016990, 4304016990, 158959754226, 354949166565, 158959754226, 4034735959800, 14805457339920, 14805457339920, 4034735959800, 79553497760100, 420797306522502, 691650582088536, 420797306522502, 79553497760100, 1302772718028600, 9220982517965400, 21853758736216200, 21853758736216200, 9220982517965400, 1302772718028600
Offset: 10
Triangle starts:
n\f [1] [2] [3] [4]
[10] 59520825;
[11] 4304016990, 4304016990;
[12] 15895975422, 354949166565, 158959754226;
[13] 4034735959800, 14805457339920, 14805457339920, 4034735959800;
[14] ...
Cf.
A035309,
A269921,
A269922,
A269923,
A269924,
A270406,
A270407,
A270408,
A270409,
A270410,
A270411,
A270412.
-
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, 5], {n, 10, 15}, {f, 1, n-9}] // Flatten (* Jean-François Alcover, Aug 10 2018 *)
-
N = 15; G = 5; 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))))
A379438
Triangle read by rows: T(n,k) is the number of sensed combinatorial maps with n edges and genus k, 0 <= k <= floor(n/2).
Original entry on oeis.org
1, 2, 4, 1, 14, 6, 57, 46, 4, 312, 452, 106, 2071, 4852, 2382, 131, 15030, 52972, 46680, 8158, 117735, 587047, 830848, 313611, 14118, 967850, 6550808, 13804864, 9326858, 1369446, 8268816, 73483256, 218353000, 236095958, 74803564, 2976853, 72833730, 827801468, 3328822880, 5345316004, 3023693380, 391288854
Offset: 0
Triangle begins:
n\k [0] [1] [2] [3] [4]
[0] 1;
[1] 2;
[2] 4, 1;
[3] 14, 6;
[4] 57, 46, 4;
[5] 312, 452, 106;
[6] 2071, 4852, 2382, 131;
[7] 15030, 52972, 46680, 8158;
[8] 117735, 587047, 830848, 313611, 14118;
[9] 967850, 6550808, 13804864, 9326858, 1369446;
...
- Andrew Howroyd, Table of n, a(n) for n = 0..120 (rows 0..20)
- Antonio Breda d'Azevedo, Alexander Mednykh and Roman Nedela, Enumeration of maps regardless of genus: Geometric approach, Discrete Mathematics, Volume 310, 2010, Pages 1184-1203.
- Timothy R. Walsh, Alain Giorgetti, and Alexander Mednykh, Enumeration of unrooted orientable maps of arbitrary genus by number of edges and vertices, Discrete Math. 312 (2012), no. 17, 2660--2671. MR2935417.
Columns 0..10 are
A006384,
A006386,
A104595,
A104596,
A215019,
A239918,
A239919,
A239921,
A239922,
A239923,
A239924.
A379439
Triangle read by rows: T(n,k) is the number of unsensed combinatorial maps with n edges and genus k, 0 <= k <= floor(n/2).
Original entry on oeis.org
1, 2, 4, 1, 14, 6, 52, 40, 4, 248, 320, 76, 1416, 2946, 1395, 82, 9172, 29364, 24950, 4348, 66366, 309558, 427336, 160050, 7258, 518868, 3365108, 6987100, 4696504, 688976, 4301350, 37246245, 109761827, 118353618, 37466297, 1491629, 37230364, 416751008, 1668376886, 2675297588, 1512650776, 195728778
Offset: 0
Triangle begins:
n\k [0] [1] [2] [3] [4]
[0] 1;
[1] 2;
[2] 4, 1;
[3] 14, 6;
[4] 52, 40, 4;
[5] 248, 320, 76;
[6] 1416, 2946, 1395, 82;
[7] 9172, 29364, 24950, 4348;
[8] 66366, 309558, 427336, 160050, 7258;
[9] 518868, 3365108, 6987100, 4696504, 688976;
A269923
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 3.
Original entry on oeis.org
1485, 56628, 56628, 1169740, 2668750, 1169740, 17454580, 66449432, 66449432, 17454580, 211083730, 1171704435, 1955808460, 1171704435, 211083730, 2198596400, 16476937840, 40121261136, 40121261136, 16476937840, 2198596400, 20465052608, 196924458720, 647739636160
Offset: 6
Triangle starts:
n\f [1] [2] [3] [4] [5]
[6] 1485;
[7] 56628, 56628;
[8] 1169740, 2668750, 1169740;
[9] 17454580, 66449432, 66449432, 17454580;
[10] 211083730, 1171704435, 1955808460, 1171704435, 211083730;
[11] ...
-
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, 3], {n, 6, 12}, {f, 1, n-5}] // Flatten (* Jean-François Alcover, Aug 10 2018 *)
-
N = 12; G = 3; 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))))
A238396
Triangle T(n,k) read by rows: T(n,k) is the number of rooted genus-k maps with n edges, n>=0, 0<=k<=n.
Original entry on oeis.org
1, 2, 0, 9, 1, 0, 54, 20, 0, 0, 378, 307, 21, 0, 0, 2916, 4280, 966, 0, 0, 0, 24057, 56914, 27954, 1485, 0, 0, 0, 208494, 736568, 650076, 113256, 0, 0, 0, 0, 1876446, 9370183, 13271982, 5008230, 225225, 0, 0, 0, 0, 17399772, 117822512, 248371380, 167808024, 24635754, 0, 0, 0, 0, 0, 165297834, 1469283166, 4366441128, 4721384790, 1495900107, 59520825, 0
Offset: 0
Triangle starts:
00: 1,
01: 2, 0,
02: 9, 1, 0,
03: 54, 20, 0, 0,
04: 378, 307, 21, 0, 0,
05: 2916, 4280, 966, 0, 0, 0,
06: 24057, 56914, 27954, 1485, 0, 0, 0,
07: 208494, 736568, 650076, 113256, 0, 0, 0, 0,
08: 1876446, 9370183, 13271982, 5008230, 225225, 0, 0, 0, 0,
09: 17399772, 117822512, 248371380, 167808024, 24635754, 0, ...,
10: 165297834, 1469283166, 4366441128, 4721384790, 1495900107, 59520825, 0, ...,
11: 1602117468, 18210135416, 73231116024, 117593590752, 66519597474, 8608033980, 0, ...,
12: 15792300756, 224636864830, 1183803697278, 2675326679856, 2416610807964, 672868675017, 24325703325, 0, ...,
...
- David M. Jackson and Terry I. Visentin, An Atlas of the Smaller Maps in Orientable and Nonorientable Surfaces, Chapman & Hall/CRC, circa 2000. See page 227.
Columns k for 0<=k<=10 are:
A000168,
A006300,
A006301,
A104742,
A215402,
A238355,
A238356,
A238357,
A238358,
A238359,
A238360.
See
A267180 for nonorientable analog.
The triangle without the zeros is
A269919.
-
T[0, 0] = 1; T[n_, g_] /; g < 0 || g > n/2 = 0; T[n_, g_] := T[n, g] = ((4n - 2)/3 T[n-1, g] + (2n-3)(2n-2)(2n-1)/12 T[n-2, g-1] + 1/2 Sum[(2k-1)(2(n - k)-1) T[k-1, i] T[n-k-1, g-i] , {k, 1, n-1}, {i, 0, g}])/((n+1)/6);
Table[T[n, g], {n, 0, 10}, {g, 0, n}] // Flatten (* Jean-François Alcover, Jul 19 2018, after Gheorghe Coserea *)
-
N=20;
MEM=matrix(N+1,N+1, r,c, -1); \\ for memoization
Q(n,g)=
{
if (n<0, return( (g<=0) ) ); \\ not given in paper
if (g<0, return( 0 ) ); \\ not given in paper
if (n<=0, return( g==0 ) ); \\ as in paper
my( m = MEM[n+1,g+1] );
if ( m != -1, return(m) ); \\ memoized value
my( t=0 );
t += (4*n-2)/3 * Q(n-1, g);
t += (2*n-3)*(2*n-2)*(2*n-1)/12 * Q(n-2, g-1);
my(l, j);
t += 1/2*
sum(k=1, n-1, l=n-k; \\ l+k == n, both >= 1
sum(i=0, g, j=g-i; \\ i+j == g, both >= 0
(2*k-1)*(2*l-1) * Q(k-1, i) * Q(l-1, j)
);
);
t *= 6/(n+1);
MEM[n+1, g+1] = t; \\ memoize
return(t);
}
for (n=0, N, for (g=0, n, print1(Q(n, g),", "); ); print(); ); /* print triangle */
A380622
Array read by antidiagonals: T(n,k) is the number of rooted k-regular combinatorial maps with n vertices, n >= 0, k >= 1.
Original entry on oeis.org
1, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 3, 5, 1, 0, 1, 0, 24, 0, 1, 0, 1, 15, 189, 297, 60, 1, 0, 1, 0, 1695, 0, 4896, 0, 1, 0, 1, 105, 19305, 472200, 869400, 100278, 1105, 1, 0, 1, 0, 252000, 0, 242183775, 0, 2450304, 0, 1, 0, 1, 945, 3828825, 2465608950, 103694490900, 198147676875, 16482741030, 69533397, 27120, 1, 0
Offset: 0
Array begins:
============================================================
n\k | 1 2 3 4 5 6 7 8 ...
----+-------------------------------------------------------
0 | 1 1 1 1 1 1 1 1 ...
1 | 0 1 0 3 0 15 0 105 ...
2 | 1 1 5 24 189 1695 19305 252000 ...
3 | 0 1 0 297 0 472200 0 2465608950 ...
4 | 0 1 60 4896 869400 242183775 ...
5 | 0 1 0 100278 0 ...
6 | 0 1 1105 2450304 ...
7 | 0 1 0 ...
...
-
T(n,k)={my(A=O(x^(n*k+1)), g=serlaplace(serconvol(exp(x^k/k + A), exp(x^2/2 + A)))); polcoef(1 + x*deriv(g)/g, n*k)}
Comments