A249246 - cp's OEIS frontend

A249246 Start with a single equilateral triangle for n=0; for the odd n-th generation add a triangle at each expandable side of the triangles of the (n-1)-th generation (this is the "vertex to side" version); for the even n-th generation use the "vertex to vertex" version; a(n) is the number of triangles in the n-th generation.

n	a(n)
0	1
1	3
2	6
3	15
4	18
5	30
6	24
7	45
8	30
9	60
10	36
11	75
12	48
13	90
14	54
15	105
16	60
17	120
18	66
19	135
20	78
21	150
22	84
23	165
24	90
25	180
26	96
27	195
28	108
29	210
30	114
31	225
32	120
33	240
34	126
35	255
36	138
37	270
38	144
39	285
40	150
41	300
42	156
43	315
44	168
45	330
46	174
47	345
48	180
49	360
50	186
51	375
52	198
53	390
54	204
55	405
56	210
57	420
58	216
59	435

[1, 3, 6, 15, 18, 30, 24, 45, 30, 60, 36, 75, 48, 90, 54, 105, 60, 120, 66, 135, 78, 150, 84, 165, 90, 180, 96, 195, 108, 210, 114, 225, 120, 240, 126, 255, 138, 270, 144, 285, 150, 300, 156, 315, 168, 330, 174, 345, 180, 360, 186, 375, 198, 390, 204, 405, 210, 420, 216, 435]

cp's OEIS Frontend

Table of values

List of values

n	a(n)
0	1
1	3
2	6
3	15
4	18
5	30
6	24
7	45
8	30
9	60
10	36
11	75
12	48
13	90
14	54
15	105
16	60
17	120
18	66
19	135
20	78
21	150
22	84
23	165
24	90
25	180
26	96
27	195
28	108
29	210
30	114
31	225
32	120
33	240
34	126
35	255
36	138
37	270
38	144
39	285
40	150
41	300
42	156
43	315
44	168
45	330
46	174
47	345
48	180
49	360
50	186
51	375
52	198
53	390
54	204
55	405
56	210
57	420
58	216
59	435

n	a(n)
0	1
1	3
2	6
3	15
4	18
5	30
6	24
7	45
8	30
9	60
10	36
11	75
12	48
13	90
14	54
15	105
16	60
17	120
18	66
19	135
20	78
21	150
22	84
23	165
24	90
25	180
26	96
27	195
28	108
29	210
30	114
31	225
32	120
33	240
34	126
35	255
36	138
37	270
38	144
39	285
40	150
41	300
42	156
43	315
44	168
45	330
46	174
47	345
48	180
49	360
50	186
51	375
52	198
53	390
54	204
55	405
56	210
57	420
58	216
59	435

n	a(n)
0	1
1	3
2	6
3	15
4	18
5	30
6	24
7	45
8	30
9	60
10	36
11	75
12	48
13	90
14	54
15	105
16	60
17	120
18	66
19	135
20	78
21	150
22	84
23	165
24	90
25	180
26	96
27	195
28	108
29	210
30	114
31	225
32	120
33	240
34	126
35	255
36	138
37	270
38	144
39	285
40	150
41	300
42	156
43	315
44	168
45	330
46	174
47	345
48	180
49	360
50	186
51	375
52	198
53	390
54	204
55	405
56	210
57	420
58	216
59	435