A261950 - cp's OEIS frontend

A261950 Start with a single equilateral triangle for n=0; for the odd n-th generation add a triangle at each expandable vertex of the triangles of the (n-1)-th generation (this is the "side to vertex" version); for the even n-th generation use the "vertex to vertex" version; a(n) is the number of triangles added in the n-th generation.

n	a(n)
0	1
1	3
2	9
3	12
4	30
5	18
6	45
7	27
8	66
9	33
10	81
11	42
12	102
13	48
14	117
15	57
16	138
17	63
18	153
19	72
20	174
21	78
22	189
23	87
24	210
25	93
26	225
27	102
28	246
29	108
30	261
31	117
32	282
33	123
34	297
35	132
36	318
37	138
38	333
39	147
40	354
41	153
42	369
43	162
44	390
45	168
46	405

[1, 3, 9, 12, 30, 18, 45, 27, 66, 33, 81, 42, 102, 48, 117, 57, 138, 63, 153, 72, 174, 78, 189, 87, 210, 93, 225, 102, 246, 108, 261, 117, 282, 123, 297, 132, 318, 138, 333, 147, 354, 153, 369, 162, 390, 168, 405]

cp's OEIS Frontend

Table of values

List of values

n	a(n)
0	1
1	3
2	9
3	12
4	30
5	18
6	45
7	27
8	66
9	33
10	81
11	42
12	102
13	48
14	117
15	57
16	138
17	63
18	153
19	72
20	174
21	78
22	189
23	87
24	210
25	93
26	225
27	102
28	246
29	108
30	261
31	117
32	282
33	123
34	297
35	132
36	318
37	138
38	333
39	147
40	354
41	153
42	369
43	162
44	390
45	168
46	405

n	a(n)
0	1
1	3
2	9
3	12
4	30
5	18
6	45
7	27
8	66
9	33
10	81
11	42
12	102
13	48
14	117
15	57
16	138
17	63
18	153
19	72
20	174
21	78
22	189
23	87
24	210
25	93
26	225
27	102
28	246
29	108
30	261
31	117
32	282
33	123
34	297
35	132
36	318
37	138
38	333
39	147
40	354
41	153
42	369
43	162
44	390
45	168
46	405

n	a(n)
0	1
1	3
2	9
3	12
4	30
5	18
6	45
7	27
8	66
9	33
10	81
11	42
12	102
13	48
14	117
15	57
16	138
17	63
18	153
19	72
20	174
21	78
22	189
23	87
24	210
25	93
26	225
27	102
28	246
29	108
30	261
31	117
32	282
33	123
34	297
35	132
36	318
37	138
38	333
39	147
40	354
41	153
42	369
43	162
44	390
45	168
46	405