A091908 - cp's OEIS frontend

A091908 Number of interior intersection points made by the straight line segments connecting the edges of an equilateral triangle with the n-1 points resulting from a subdivision of the sides into n equal pieces, counting coinciding intersection points only once.

n	a(n)
1	0
2	1
3	12
4	13
5	48
6	49
7	108
8	109
9	192
10	193
11	300
12	301
13	432
14	433
15	576
16	589
17	768
18	769
19	972
20	961
21	1200
22	1201
23	1452
24	1405
25	1728
26	1729
27	2028
28	2029
29	2352
30	2341
31	2700
32	2701
33	3072
34	3073
35	3444
36	3469
37	3888
38	3889
39	4332
40	4297
41	4800
42	4777
43	5292
44	5293
45	5724
46	5809
47	6348

[0, 1, 12, 13, 48, 49, 108, 109, 192, 193, 300, 301, 432, 433, 576, 589, 768, 769, 972, 961, 1200, 1201, 1452, 1405, 1728, 1729, 2028, 2029, 2352, 2341, 2700, 2701, 3072, 3073, 3444, 3469, 3888, 3889, 4332, 4297, 4800, 4777, 5292, 5293, 5724, 5809, 6348]

cp's OEIS Frontend

A091908 Number of interior intersection points made by the straight line segments connecting the edges of an equilateral triangle with the n-1 points resulting from a subdivision of the sides into n equal pieces, counting coinciding intersection points only once.

Table of values

List of values