A339609 - cp's OEIS frontend

A339609 Consider a triangle drawn on the perimeter of a triangular lattice with side length n. a(n) is the number of regions inside the triangle after drawing unit circles centered at each lattice point inside the triangle.

n	a(n)
1	0
2	0
3	4
4	10
5	22
6	39
7	61
8	88
9	120
10	157
11	199
12	246
13	298
14	355
15	417
16	484
17	556
18	633
19	715
20	802
21	894
22	991
23	1093
24	1200
25	1312
26	1429
27	1551
28	1678
29	1810
30	1947
31	2089
32	2236
33	2388
34	2545
35	2707
36	2874
37	3046
38	3223
39	3405
40	3592
41	3784
42	3981
43	4183
44	4390
45	4602
46	4819
47	5041
48	5268
49	5500
50	5737

[0, 0, 4, 10, 22, 39, 61, 88, 120, 157, 199, 246, 298, 355, 417, 484, 556, 633, 715, 802, 894, 991, 1093, 1200, 1312, 1429, 1551, 1678, 1810, 1947, 2089, 2236, 2388, 2545, 2707, 2874, 3046, 3223, 3405, 3592, 3784, 3981, 4183, 4390, 4602, 4819, 5041, 5268, 5500, 5737]

cp's OEIS Frontend

A339609 Consider a triangle drawn on the perimeter of a triangular lattice with side length n. a(n) is the number of regions inside the triangle after drawing unit circles centered at each lattice point inside the triangle.

Table of values

List of values