A333906 - cp's OEIS frontend

A333906 For n >= 2, a(n) = Sum_{k=2..n} prevpower2(k) + nextpower2(k) - 2*k, where prevpower2(k) is the largest power of 2 < k, nextpower2(k) is the smallest power of 2 > k.

n	a(n)
2	1
3	1
4	3
5	5
6	5
7	3
8	7
9	13
10	17
11	19
12	19
13	17
14	13
15	7
16	15
17	29
18	41
19	51
20	59
21	65
22	69
23	71
24	71
25	69
26	65
27	59
28	51
29	41
30	29
31	15
32	31
33	61
34	89
35	115
36	139
37	161
38	181
39	199
40	215
41	229
42	241
43	251
44	259
45	265
46	269
47	271
48	271
49	269
50	265
51	259
52	251
53	241
54	229
55	215
56	199
57	181
58	161

[1, 1, 3, 5, 5, 3, 7, 13, 17, 19, 19, 17, 13, 7, 15, 29, 41, 51, 59, 65, 69, 71, 71, 69, 65, 59, 51, 41, 29, 15, 31, 61, 89, 115, 139, 161, 181, 199, 215, 229, 241, 251, 259, 265, 269, 271, 271, 269, 265, 259, 251, 241, 229, 215, 199, 181, 161]

cp's OEIS Frontend

A333906 For n >= 2, a(n) = Sum_{k=2..n} prevpower2(k) + nextpower2(k) - 2*k, where prevpower2(k) is the largest power of 2 < k, nextpower2(k) is the smallest power of 2 > k.

Table of values

List of values

n	a(n)
2	1
3	1
4	3
5	5
6	5
7	3
8	7
9	13
10	17
11	19
12	19
13	17
14	13
15	7
16	15
17	29
18	41
19	51
20	59
21	65
22	69
23	71
24	71
25	69
26	65
27	59
28	51
29	41
30	29
31	15
32	31
33	61
34	89
35	115
36	139
37	161
38	181
39	199
40	215
41	229
42	241
43	251
44	259
45	265
46	269
47	271
48	271
49	269
50	265
51	259
52	251
53	241
54	229
55	215
56	199
57	181
58	161

n	a(n)
2	1
3	1
4	3
5	5
6	5
7	3
8	7
9	13
10	17
11	19
12	19
13	17
14	13
15	7
16	15
17	29
18	41
19	51
20	59
21	65
22	69
23	71
24	71
25	69
26	65
27	59
28	51
29	41
30	29
31	15
32	31
33	61
34	89
35	115
36	139
37	161
38	181
39	199
40	215
41	229
42	241
43	251
44	259
45	265
46	269
47	271
48	271
49	269
50	265
51	259
52	251
53	241
54	229
55	215
56	199
57	181
58	161

n	a(n)
2	1
3	1
4	3
5	5
6	5
7	3
8	7
9	13
10	17
11	19
12	19
13	17
14	13
15	7
16	15
17	29
18	41
19	51
20	59
21	65
22	69
23	71
24	71
25	69
26	65
27	59
28	51
29	41
30	29
31	15
32	31
33	61
34	89
35	115
36	139
37	161
38	181
39	199
40	215
41	229
42	241
43	251
44	259
45	265
46	269
47	271
48	271
49	269
50	265
51	259
52	251
53	241
54	229
55	215
56	199
57	181
58	161