A294791
Triangle read by rows, 1 <= k <= n: T(n,k) = non-isomorphic colorings of a toroidal n X k grid using exactly two colors under translational symmetry and swappable colors.
Original entry on oeis.org
0, 1, 4, 1, 7, 31, 3, 23, 179, 2107, 3, 55, 1095, 26271, 671103, 7, 189, 7327, 350063, 17896831, 954459519, 9, 595, 49939, 4794087, 490853415, 52357746895, 5744387279871, 19, 2101, 349715, 67115111, 13743921631, 2932032057731, 643371380132743, 144115188277194943, 29, 7315, 2485591, 954444607, 390937468407, 166799988703927, 73201365371896619
Offset: 1
For the 2 X 2 grid and two colors we find T(2,2) = 4:
+---+ +---+ +---+ +---+
|X| | |X| | |X|X| |X| |
+-+-+ +-+-+ +-+-+ +-+-+
| | | | |X| | | | |X| |
+-+-+ +-+-+ +-+-+ +-+-+
- F. Harary and E. Palmer, Graphical Enumeration, Academic Press, 1973.
A294792
Triangle read by rows, 1 <= k <= n: T(n,k) = non-isomorphic colorings of a toroidal n X k grid using exactly three colors under translational symmetry and swappable colors.
Original entry on oeis.org
0, 0, 3, 1, 18, 345, 2, 136, 7254, 447156, 5, 946, 158355, 29032254, 5647919665, 18, 7324, 3580802, 1961010826, 1143822046786, 694881637942816, 43, 56450, 82968843, 136166703562, 238244961999013, 434202285631866206, 813943290958393433377, 126, 447138, 1960981598, 9651082393912, 50656925726930746, 276966813318877426118, 1557582240509759704455566
Offset: 1
- F. Harary and E. Palmer, Graphical Enumeration, Academic Press, 1973.
A294793
Triangle read by rows, 1 <= k <= n: T(n,k) = non-isomorphic colorings of a toroidal n X k grid using exactly four colors under translational symmetry and swappable colors.
Original entry on oeis.org
0, 0, 1, 0, 13, 874, 1, 235, 51075, 10741819, 2, 3437, 2823766, 2261625725, 1870851589562, 13, 51275, 155495153, 486711524815, 1600136051453135, 5465007068038102643, 50, 742651, 8643289534, 107092397450897, 1405227969932349726, 19188864521773558375127, 269482732023591671431784330, 221, 10741763, 486710971595, 24009547064476683
Offset: 1
- F. Harary and E. Palmer, Graphical Enumeration, Academic Press, 1973.
A294684
Triangle read by rows: T(n,k) is the number of non-isomorphic colorings of a toroidal n X k grid using exactly two colors under translational symmetry, 1 <= k <= n.
Original entry on oeis.org
0, 1, 5, 2, 12, 62, 4, 38, 350, 4154, 6, 106, 2190, 52486, 1342206, 12, 360, 14622, 699598, 35792566, 1908897150, 18, 1180, 99878, 9587578, 981706830, 104715443850, 11488774559742, 34, 4148, 699250, 134223974, 27487816990, 5864063066498, 1286742755471398, 288230376353050814
Offset: 1
Triangle begins:
0;
1, 5;
2, 12, 62;
4, 38, 350, 4154;
6, 106, 2190, 52486, 1342206;
12, 360, 14622, 699598, 35792566, 1908897150;
18, 1180, 99878, 9587578, 981706830, 104715443850, 11488774559742;
...
For the 2 X 2 and two colors we find
+---+ +---+ +---+ +---+ +---+
|X| | | |X| |X| | |X|X| |X| |
+-+-+ +-+-+ +-+-+ +-+-+ +-+-+
| | | |X|X| | |X| | | | |X| |
+-+-+ +-+-+ +-+-+ +-+-+ +-+-+
- F. Harary and E. Palmer, Graphical Enumeration, Academic Press, 1973.
-
With[{Q = 2}, Table[(Q!/n/k) Sum[Sum[EulerPhi[d] EulerPhi[f] StirlingS2[GCD[d, f] (n/d) (k/f), Q], {f, Divisors@ k}], {d, Divisors@ n}], {n, 8}, {k, n}]] // Flatten (* Michael De Vlieger, Nov 08 2017 *)
-
T(n,m) = {2*sumdiv(n, d, sumdiv(m, e, eulerphi(d) * eulerphi(e) * stirling(n*m/lcm(d,e), 2, 2) ))/(n*m)} \\ Andrew Howroyd, Oct 05 2024
A294685
Triangle read by rows: T(n,k) is the number of non-isomorphic colorings of a toroidal n X k grid using exactly three colors under translational symmetry, 1 <= k <= n.
Original entry on oeis.org
0, 0, 9, 2, 91, 2022, 9, 738, 43315, 2679246, 30, 5613, 950062, 174184755, 33887517990, 91, 43404, 21480921, 11765865678, 6862930841141, 4169289730628814, 258, 338259, 497812638, 816999710223, 1429469771994078, 2605213713043722909, 4883659745750360600262, 729, 2679228, 11765822365, 57906482267826, 303941554100145501
Offset: 1
Triangle begins:
0;
0, 9;
2, 91, 2022;
9, 738, 43315, 2679246;
30, 5613, 950062, 174184755, 33887517990;
91, 43404, 21480921, 11765865678, 6862930841141, 4169289730628814;
...
- F. Harary and E. Palmer, Graphical Enumeration, Academic Press, 1973.
-
T(n,m)=6*sumdiv(n, d, sumdiv(m, e, eulerphi(d) * eulerphi(e) * stirling(n*m/lcm(d,e), 3, 2) ))/(n*m) \\ Andrew Howroyd, Oct 05 2024
A294687
Triangle read by rows: T(n,k) is the number of non-isomorphic colorings of a toroidal n X k grid using exactly five colors under translational symmetry, 1 <= k <= n.
Original entry on oeis.org
0, 0, 0, 0, 300, 92680, 0, 15750, 13794150, 8221452750, 24, 510312, 1686135376, 4495236798162, 11696087875731720, 300, 13794450, 193054017440, 2425003938178050, 30852000867277668428, 403564024914127655401650, 2400, 343501500, 21664357535320, 1317601563731383350, 82985159653854019928352, 5411356249329837891442095560
Offset: 1
Triangle begins:
0;
0, 0;
0, 300, 92680;
0, 15750, 13794150, 8221452750;
24, 510312, 1686135376, 4495236798162, 11696087875731720;
...
- F. Harary and E. Palmer, Graphical Enumeration, Academic Press, 1973.
-
T(n,m)=my(k=5); k!*sumdiv(n, d, sumdiv(m, e, eulerphi(d) * eulerphi(e) * stirling(n*m/lcm(d,e), k, 2) ))/(n*m) \\ Andrew Howroyd, Oct 05 2024
A294794
Triangle read by rows, 1 <= k <= n: T(n,k) = non-isomorphic colorings of a toroidal n X k grid using exactly five colors under translational symmetry and swappable colors.
Original entry on oeis.org
0, 0, 0, 0, 3, 775, 0, 145, 115100, 68522769, 1, 4281, 14051164, 37460388596, 97467398965031, 3, 115381, 1608801153, 20208371722051, 257100007425866689, 3363033541015148835823, 20, 2863227, 180536313547, 10980013072900632, 691542997115450167856, 45094635411084308447578413, 3020745549854628001139950947779, 136, 68522707
Offset: 1
- F. Harary and E. Palmer, Graphical Enumeration, Academic Press, 1973.
A376824
Number of colorings of a toroidal n X n grid using exactly four colors under translational symmetry.
Original entry on oeis.org
0, 6, 20720, 257706024, 44900438149488, 131160169581733489616, 6467585568566200114362823920, 5316911768534424725926923896066891424, 72172920340122292837562997014593985220649867760, 16069380442569287654590340470284256047904187412954757496784
Offset: 1
Showing 1-8 of 8 results.
Comments