A380235 Triangle read by rows: T(n,k) is the number of n edge non-orientable genus k maps.
1, 4, 2, 19, 16, 8, 106, 137, 128, 47, 709, 1254, 1890, 1372, 473, 5356, 12597, 27036, 31007, 22556, 7190, 44558, 133518, 379491, 611322, 704066, 469632, 144904, 397146, 1464725, 5229092, 11017122, 17691240, 18521632, 11990766, 3534490, 3716039, 16373700, 70805740, 186044902, 387965547, 563764626, 571333104, 352456980, 100895667
Offset: 1
Examples
Triangle begins:
1;
4, 2;
19, 16, 8;
106, 137, 128, 47;
709, 1254, 1890, 1372, 473;
5356, 12597, 27036, 31007, 22556, 7190;
44558, 133518, 379491, 611322, 704066, 469632, 144904;
...
Links
- Andrew Howroyd, Table of n, a(n) for n = 1..105 (rows 1..14)
- Evgeniy Krasko and Alexander Omelchenko, Enumeration of Unsensed Orientable Maps on Surfaces of a Given Genus, arXiv:1712.10139 [math.CO], 2017, see Appendix Tables 5-7.
- Evgeniy Krasko, Maps on non-orientable surfaces, 2017 (data file).