A331782 - cp's OEIS frontend

A331782 Total number of vertices in graph formed 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	3
2	7
3	21
4	25
5	63
6	67
7	129
8	133
9	219
10	223
11	333
12	337
13	471
14	475
15	621
16	637
17	819
18	823
19	1029
20	1021
21	1263
22	1267
23	1521
24	1477
25	1803
26	1807
27	2109
28	2113
29	2439
30	2431
31	2793
32	2797
33	3171
34	3175
35	3549
36	3577
37	3999
38	4003
39	4449
40	4417
41	4923
42	4903
43	5421
44	5425
45	5859
46	5947
47	6489
48	6397
49	7059
50	7063
51	7653
52	7657
53	8271
54	8275
55	8889

[3, 7, 21, 25, 63, 67, 129, 133, 219, 223, 333, 337, 471, 475, 621, 637, 819, 823, 1029, 1021, 1263, 1267, 1521, 1477, 1803, 1807, 2109, 2113, 2439, 2431, 2793, 2797, 3171, 3175, 3549, 3577, 3999, 4003, 4449, 4417, 4923, 4903, 5421, 5425, 5859, 5947, 6489, 6397, 7059, 7063, 7653, 7657, 8271, 8275, 8889]

cp's OEIS Frontend

A331782 Total number of vertices in graph formed 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