A261951 - cp's OEIS frontend

A261951 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 "vertex to vertex" version); for the even n-th generation use the "vertex to side" 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	24
5	24
6	39
7	27
8	54
9	33
10	69
11	42
12	84
13	54
14	99
15	57
16	114
17	63
18	129
19	72
20	144
21	84
22	159
23	87
24	174
25	93
26	189
27	102
28	204
29	114
30	219
31	117
32	234
33	123
34	249
35	132
36	264
37	144
38	279
39	147
40	294
41	153
42	309
43	162
44	324
45	174
46	339
47	177
48	354

[1, 3, 9, 12, 24, 24, 39, 27, 54, 33, 69, 42, 84, 54, 99, 57, 114, 63, 129, 72, 144, 84, 159, 87, 174, 93, 189, 102, 204, 114, 219, 117, 234, 123, 249, 132, 264, 144, 279, 147, 294, 153, 309, 162, 324, 174, 339, 177, 354]

cp's OEIS Frontend

Table of values

List of values

n	a(n)
0	1
1	3
2	9
3	12
4	24
5	24
6	39
7	27
8	54
9	33
10	69
11	42
12	84
13	54
14	99
15	57
16	114
17	63
18	129
19	72
20	144
21	84
22	159
23	87
24	174
25	93
26	189
27	102
28	204
29	114
30	219
31	117
32	234
33	123
34	249
35	132
36	264
37	144
38	279
39	147
40	294
41	153
42	309
43	162
44	324
45	174
46	339
47	177
48	354

n	a(n)
0	1
1	3
2	9
3	12
4	24
5	24
6	39
7	27
8	54
9	33
10	69
11	42
12	84
13	54
14	99
15	57
16	114
17	63
18	129
19	72
20	144
21	84
22	159
23	87
24	174
25	93
26	189
27	102
28	204
29	114
30	219
31	117
32	234
33	123
34	249
35	132
36	264
37	144
38	279
39	147
40	294
41	153
42	309
43	162
44	324
45	174
46	339
47	177
48	354

n	a(n)
0	1
1	3
2	9
3	12
4	24
5	24
6	39
7	27
8	54
9	33
10	69
11	42
12	84
13	54
14	99
15	57
16	114
17	63
18	129
19	72
20	144
21	84
22	159
23	87
24	174
25	93
26	189
27	102
28	204
29	114
30	219
31	117
32	234
33	123
34	249
35	132
36	264
37	144
38	279
39	147
40	294
41	153
42	309
43	162
44	324
45	174
46	339
47	177
48	354