A356721 - cp's OEIS frontend

A356721 Numbers written using exactly two distinct Roman numerals.

n	a(n)
1	4
2	6
3	7
4	8
5	9
6	11
7	12
8	13
9	15
10	19
11	21
12	22
13	23
14	25
15	29
16	31
17	32
18	33
19	35
20	39
21	40
22	51
23	52
24	53
25	55
26	60
27	70
28	80
29	90
30	101
31	102
32	103
33	105
34	110
35	120
36	130
37	150
38	190
39	201
40	202
41	203
42	205
43	210
44	220
45	230
46	250
47	290
48	301
49	302
50	303
51	305
52	310
53	320
54	330
55	350
56	390
57	400
58	501
59	502

[4, 6, 7, 8, 9, 11, 12, 13, 15, 19, 21, 22, 23, 25, 29, 31, 32, 33, 35, 39, 40, 51, 52, 53, 55, 60, 70, 80, 90, 101, 102, 103, 105, 110, 120, 130, 150, 190, 201, 202, 203, 205, 210, 220, 230, 250, 290, 301, 302, 303, 305, 310, 320, 330, 350, 390, 400, 501, 502]

cp's OEIS Frontend

A356721 Numbers written using exactly two distinct Roman numerals.

Table of values

List of values

n	a(n)
1	4
2	6
3	7
4	8
5	9
6	11
7	12
8	13
9	15
10	19
11	21
12	22
13	23
14	25
15	29
16	31
17	32
18	33
19	35
20	39
21	40
22	51
23	52
24	53
25	55
26	60
27	70
28	80
29	90
30	101
31	102
32	103
33	105
34	110
35	120
36	130
37	150
38	190
39	201
40	202
41	203
42	205
43	210
44	220
45	230
46	250
47	290
48	301
49	302
50	303
51	305
52	310
53	320
54	330
55	350
56	390
57	400
58	501
59	502

n	a(n)
1	4
2	6
3	7
4	8
5	9
6	11
7	12
8	13
9	15
10	19
11	21
12	22
13	23
14	25
15	29
16	31
17	32
18	33
19	35
20	39
21	40
22	51
23	52
24	53
25	55
26	60
27	70
28	80
29	90
30	101
31	102
32	103
33	105
34	110
35	120
36	130
37	150
38	190
39	201
40	202
41	203
42	205
43	210
44	220
45	230
46	250
47	290
48	301
49	302
50	303
51	305
52	310
53	320
54	330
55	350
56	390
57	400
58	501
59	502

n	a(n)
1	4
2	6
3	7
4	8
5	9
6	11
7	12
8	13
9	15
10	19
11	21
12	22
13	23
14	25
15	29
16	31
17	32
18	33
19	35
20	39
21	40
22	51
23	52
24	53
25	55
26	60
27	70
28	80
29	90
30	101
31	102
32	103
33	105
34	110
35	120
36	130
37	150
38	190
39	201
40	202
41	203
42	205
43	210
44	220
45	230
46	250
47	290
48	301
49	302
50	303
51	305
52	310
53	320
54	330
55	350
56	390
57	400
58	501
59	502