A050042 - cp's OEIS frontend

A050042 a(n) = a(n-1) + a(m) for n >= 4, where m = n - 1 - 2^p and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 2, and a(3) = 1.

n	a(n)
1	1
2	2
3	1
4	2
5	4
6	5
7	7
8	8
9	10
10	11
11	13
12	14
13	16
14	20
15	25
16	32
17	40
18	41
19	43
20	44
21	46
22	50
23	55
24	62
25	70
26	80
27	91
28	104
29	118
30	134
31	154
32	179
33	211
34	212
35	214
36	215
37	217
38	221
39	226
40	233
41	241
42	251
43	262
44	275
45	289
46	305
47	325
48	350
49	382

[1, 2, 1, 2, 4, 5, 7, 8, 10, 11, 13, 14, 16, 20, 25, 32, 40, 41, 43, 44, 46, 50, 55, 62, 70, 80, 91, 104, 118, 134, 154, 179, 211, 212, 214, 215, 217, 221, 226, 233, 241, 251, 262, 275, 289, 305, 325, 350, 382]

cp's OEIS Frontend

A050042 a(n) = a(n-1) + a(m) for n >= 4, where m = n - 1 - 2^p and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 2, and a(3) = 1.

Table of values

List of values

n	a(n)
1	1
2	2
3	1
4	2
5	4
6	5
7	7
8	8
9	10
10	11
11	13
12	14
13	16
14	20
15	25
16	32
17	40
18	41
19	43
20	44
21	46
22	50
23	55
24	62
25	70
26	80
27	91
28	104
29	118
30	134
31	154
32	179
33	211
34	212
35	214
36	215
37	217
38	221
39	226
40	233
41	241
42	251
43	262
44	275
45	289
46	305
47	325
48	350
49	382

n	a(n)
1	1
2	2
3	1
4	2
5	4
6	5
7	7
8	8
9	10
10	11
11	13
12	14
13	16
14	20
15	25
16	32
17	40
18	41
19	43
20	44
21	46
22	50
23	55
24	62
25	70
26	80
27	91
28	104
29	118
30	134
31	154
32	179
33	211
34	212
35	214
36	215
37	217
38	221
39	226
40	233
41	241
42	251
43	262
44	275
45	289
46	305
47	325
48	350
49	382

n	a(n)
1	1
2	2
3	1
4	2
5	4
6	5
7	7
8	8
9	10
10	11
11	13
12	14
13	16
14	20
15	25
16	32
17	40
18	41
19	43
20	44
21	46
22	50
23	55
24	62
25	70
26	80
27	91
28	104
29	118
30	134
31	154
32	179
33	211
34	212
35	214
36	215
37	217
38	221
39	226
40	233
41	241
42	251
43	262
44	275
45	289
46	305
47	325
48	350
49	382