A381678 - cp's OEIS frontend

A381678 a(n) is the least exponent k such that there are exactly n 1's in the decimal expansion of 11^k, or -1 if no such k exists.

n	a(n)
1	0
2	1
3	5
4	11
5	21
6	26
7	31
8	41
9	51
10	55
11	58
12	54
13	72
14	73
15	91
16	113
17	116
18	107
19	150
20	147
21	103
22	152
23	158
24	199
25	181
26	202
27	165
28	186
29	215
30	218
31	238
32	231
33	273
34	255
35	266
36	232
37	302
38	317
39	297
40	294
41	327
42	320
43	293
44	398
45	339
46	340
47	350
48	356
49	406
50	361
51	380
52	421
53	391
54	330
55	401
56	429
57	438
58	474
59	388

[0, 1, 5, 11, 21, 26, 31, 41, 51, 55, 58, 54, 72, 73, 91, 113, 116, 107, 150, 147, 103, 152, 158, 199, 181, 202, 165, 186, 215, 218, 238, 231, 273, 255, 266, 232, 302, 317, 297, 294, 327, 320, 293, 398, 339, 340, 350, 356, 406, 361, 380, 421, 391, 330, 401, 429, 438, 474, 388]

cp's OEIS Frontend

A381678 a(n) is the least exponent k such that there are exactly n 1's in the decimal expansion of 11^k, or -1 if no such k exists.

Table of values

List of values

n	a(n)
1	0
2	1
3	5
4	11
5	21
6	26
7	31
8	41
9	51
10	55
11	58
12	54
13	72
14	73
15	91
16	113
17	116
18	107
19	150
20	147
21	103
22	152
23	158
24	199
25	181
26	202
27	165
28	186
29	215
30	218
31	238
32	231
33	273
34	255
35	266
36	232
37	302
38	317
39	297
40	294
41	327
42	320
43	293
44	398
45	339
46	340
47	350
48	356
49	406
50	361
51	380
52	421
53	391
54	330
55	401
56	429
57	438
58	474
59	388

n	a(n)
1	0
2	1
3	5
4	11
5	21
6	26
7	31
8	41
9	51
10	55
11	58
12	54
13	72
14	73
15	91
16	113
17	116
18	107
19	150
20	147
21	103
22	152
23	158
24	199
25	181
26	202
27	165
28	186
29	215
30	218
31	238
32	231
33	273
34	255
35	266
36	232
37	302
38	317
39	297
40	294
41	327
42	320
43	293
44	398
45	339
46	340
47	350
48	356
49	406
50	361
51	380
52	421
53	391
54	330
55	401
56	429
57	438
58	474
59	388

n	a(n)
1	0
2	1
3	5
4	11
5	21
6	26
7	31
8	41
9	51
10	55
11	58
12	54
13	72
14	73
15	91
16	113
17	116
18	107
19	150
20	147
21	103
22	152
23	158
24	199
25	181
26	202
27	165
28	186
29	215
30	218
31	238
32	231
33	273
34	255
35	266
36	232
37	302
38	317
39	297
40	294
41	327
42	320
43	293
44	398
45	339
46	340
47	350
48	356
49	406
50	361
51	380
52	421
53	391
54	330
55	401
56	429
57	438
58	474
59	388