A047839 - cp's OEIS frontend

A047839 a(n) = n + floor( sqrt(2*n) ).

n	a(n)
1	2
2	4
3	5
4	6
5	8
6	9
7	10
8	12
9	13
10	14
11	15
12	16
13	18
14	19
15	20
16	21
17	22
18	24
19	25
20	26
21	27
22	28
23	29
24	30
25	32
26	33
27	34
28	35
29	36
30	37
31	38
32	40
33	41
34	42
35	43
36	44
37	45
38	46
39	47
40	48
41	50
42	51
43	52
44	53
45	54
46	55
47	56
48	57
49	58
50	60
51	61
52	62
53	63
54	64
55	65
56	66
57	67
58	68
59	69
60	70
61	72
62	73
63	74
64	75
65	76
66	77
67	78
68	79

[2, 4, 5, 6, 8, 9, 10, 12, 13, 14, 15, 16, 18, 19, 20, 21, 22, 24, 25, 26, 27, 28, 29, 30, 32, 33, 34, 35, 36, 37, 38, 40, 41, 42, 43, 44, 45, 46, 47, 48, 50, 51, 52, 53, 54, 55, 56, 57, 58, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 72, 73, 74, 75, 76, 77, 78, 79]

cp's OEIS Frontend

A047839 a(n) = n + floor( sqrt(2*n) ).

Table of values

List of values

n	a(n)
1	2
2	4
3	5
4	6
5	8
6	9
7	10
8	12
9	13
10	14
11	15
12	16
13	18
14	19
15	20
16	21
17	22
18	24
19	25
20	26
21	27
22	28
23	29
24	30
25	32
26	33
27	34
28	35
29	36
30	37
31	38
32	40
33	41
34	42
35	43
36	44
37	45
38	46
39	47
40	48
41	50
42	51
43	52
44	53
45	54
46	55
47	56
48	57
49	58
50	60
51	61
52	62
53	63
54	64
55	65
56	66
57	67
58	68
59	69
60	70
61	72
62	73
63	74
64	75
65	76
66	77
67	78
68	79

n	a(n)
1	2
2	4
3	5
4	6
5	8
6	9
7	10
8	12
9	13
10	14
11	15
12	16
13	18
14	19
15	20
16	21
17	22
18	24
19	25
20	26
21	27
22	28
23	29
24	30
25	32
26	33
27	34
28	35
29	36
30	37
31	38
32	40
33	41
34	42
35	43
36	44
37	45
38	46
39	47
40	48
41	50
42	51
43	52
44	53
45	54
46	55
47	56
48	57
49	58
50	60
51	61
52	62
53	63
54	64
55	65
56	66
57	67
58	68
59	69
60	70
61	72
62	73
63	74
64	75
65	76
66	77
67	78
68	79

n	a(n)
1	2
2	4
3	5
4	6
5	8
6	9
7	10
8	12
9	13
10	14
11	15
12	16
13	18
14	19
15	20
16	21
17	22
18	24
19	25
20	26
21	27
22	28
23	29
24	30
25	32
26	33
27	34
28	35
29	36
30	37
31	38
32	40
33	41
34	42
35	43
36	44
37	45
38	46
39	47
40	48
41	50
42	51
43	52
44	53
45	54
46	55
47	56
48	57
49	58
50	60
51	61
52	62
53	63
54	64
55	65
56	66
57	67
58	68
59	69
60	70
61	72
62	73
63	74
64	75
65	76
66	77
67	78
68	79