A261957 - cp's OEIS frontend

A261957 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 "side 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	12
6	24
7	18
8	36
9	33
10	57
11	45
12	81
13	36
14	78
15	42
16	90
17	57
18	111
19	69
20	135
21	60
22	132
23	66
24	144
25	81
26	165
27	93
28	189
29	84
30	186
31	90
32	198
33	105
34	219
35	117
36	243
37	108
38	240
39	114
40	252
41	129
42	273
43	141
44	297
45	132
46	294
47	138
48	306
49	153

[1, 3, 9, 12, 24, 12, 24, 18, 36, 33, 57, 45, 81, 36, 78, 42, 90, 57, 111, 69, 135, 60, 132, 66, 144, 81, 165, 93, 189, 84, 186, 90, 198, 105, 219, 117, 243, 108, 240, 114, 252, 129, 273, 141, 297, 132, 294, 138, 306, 153]

cp's OEIS Frontend

Table of values

List of values

n	a(n)
0	1
1	3
2	9
3	12
4	24
5	12
6	24
7	18
8	36
9	33
10	57
11	45
12	81
13	36
14	78
15	42
16	90
17	57
18	111
19	69
20	135
21	60
22	132
23	66
24	144
25	81
26	165
27	93
28	189
29	84
30	186
31	90
32	198
33	105
34	219
35	117
36	243
37	108
38	240
39	114
40	252
41	129
42	273
43	141
44	297
45	132
46	294
47	138
48	306
49	153

n	a(n)
0	1
1	3
2	9
3	12
4	24
5	12
6	24
7	18
8	36
9	33
10	57
11	45
12	81
13	36
14	78
15	42
16	90
17	57
18	111
19	69
20	135
21	60
22	132
23	66
24	144
25	81
26	165
27	93
28	189
29	84
30	186
31	90
32	198
33	105
34	219
35	117
36	243
37	108
38	240
39	114
40	252
41	129
42	273
43	141
44	297
45	132
46	294
47	138
48	306
49	153

n	a(n)
0	1
1	3
2	9
3	12
4	24
5	12
6	24
7	18
8	36
9	33
10	57
11	45
12	81
13	36
14	78
15	42
16	90
17	57
18	111
19	69
20	135
21	60
22	132
23	66
24	144
25	81
26	165
27	93
28	189
29	84
30	186
31	90
32	198
33	105
34	219
35	117
36	243
37	108
38	240
39	114
40	252
41	129
42	273
43	141
44	297
45	132
46	294
47	138
48	306
49	153