OFFSET
1,1
COMMENTS
No formula is known.
For further illustrations see A331452.
LINKS
Scott R. Shannon, Data for triangles A334691 and A334699
Scott R. Shannon, Colored illustration for n = 2
Scott R. Shannon, Image showing the k-sided cells for n = 10.
N. J. A. Sloane, "A Handbook of Integer Sequences" Fifty Years Later, arXiv:2301.03149 [math.NT], 2023, p. 20.
EXAMPLE
Triangle begins:
4;
48, 8;
204, 112, 24;
680, 384, 56, 0;
1660, 1072, 448, 76, 8;
3416, 2392, 400, 56, 0, 0;
6348, 5236, 1840, 504, 40, 0, 0;
11048, 8624, 2800, 408, 24, 0, 0, 0;
17708, 14976, 4960, 1004, 96, 4, 0, 0, 0;
27520, 22200, 7104, 1288, 136, 8, 0, 0, 0, 0;
40388, 35832, 15080, 3808, 488, 60, 0, 0, 0, 0, 0;
57360, 47160, 13856, 2272, 296, 16, 0, 0, 0, 0, 0, 0;
79108, 73572, 30800, 7788, 1152, 200, 16, 0, 0, 0, 0, 0, 0;
...
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Scott R. Shannon and N. J. A. Sloane, May 18 2020
EXTENSIONS
a(29) and beyond by Scott R. Shannon, Feb 18 2021
STATUS
approved