A064002 - cp's OEIS frontend

A064002 List pairs (i,j) with 1 <= i <= j in colexicographic order: (1,1), (1,2), (2,2), (1,3), (2,3), (3,3), (1,4), ... Let a(1) = 1. Then for n>=2 if the (n-1)-st pair is (i,j) then a(n) = a(i) + a(j) + 1.

n	a(n)
1	1
2	3
3	5
4	7
5	7
6	9
7	11
8	9
9	11
10	13
11	15
12	9
13	11
14	13
15	15
16	15
17	11
18	13
19	15
20	17
21	17
22	19
23	13
24	15
25	17
26	19
27	19
28	21
29	23
30	11
31	13
32	15
33	17
34	17
35	19
36	21
37	19
38	13
39	15
40	17
41	19
42	19
43	21
44	23
45	21
46	23
47	15
48	17
49	19
50	21
51	21
52	23
53	25
54	23
55	25
56	27
57	17
58	19
59	21
60	23
61	23
62	25
63	27
64	25
65	27
66	29
67	31
68	11
69	13
70	15
71	17
72	17

[1, 3, 5, 7, 7, 9, 11, 9, 11, 13, 15, 9, 11, 13, 15, 15, 11, 13, 15, 17, 17, 19, 13, 15, 17, 19, 19, 21, 23, 11, 13, 15, 17, 17, 19, 21, 19, 13, 15, 17, 19, 19, 21, 23, 21, 23, 15, 17, 19, 21, 21, 23, 25, 23, 25, 27, 17, 19, 21, 23, 23, 25, 27, 25, 27, 29, 31, 11, 13, 15, 17, 17]

cp's OEIS Frontend

A064002 List pairs (i,j) with 1 <= i <= j in colexicographic order: (1,1), (1,2), (2,2), (1,3), (2,3), (3,3), (1,4), ... Let a(1) = 1. Then for n>=2 if the (n-1)-st pair is (i,j) then a(n) = a(i) + a(j) + 1.

Table of values

List of values

n	a(n)
1	1
2	3
3	5
4	7
5	7
6	9
7	11
8	9
9	11
10	13
11	15
12	9
13	11
14	13
15	15
16	15
17	11
18	13
19	15
20	17
21	17
22	19
23	13
24	15
25	17
26	19
27	19
28	21
29	23
30	11
31	13
32	15
33	17
34	17
35	19
36	21
37	19
38	13
39	15
40	17
41	19
42	19
43	21
44	23
45	21
46	23
47	15
48	17
49	19
50	21
51	21
52	23
53	25
54	23
55	25
56	27
57	17
58	19
59	21
60	23
61	23
62	25
63	27
64	25
65	27
66	29
67	31
68	11
69	13
70	15
71	17
72	17

n	a(n)
1	1
2	3
3	5
4	7
5	7
6	9
7	11
8	9
9	11
10	13
11	15
12	9
13	11
14	13
15	15
16	15
17	11
18	13
19	15
20	17
21	17
22	19
23	13
24	15
25	17
26	19
27	19
28	21
29	23
30	11
31	13
32	15
33	17
34	17
35	19
36	21
37	19
38	13
39	15
40	17
41	19
42	19
43	21
44	23
45	21
46	23
47	15
48	17
49	19
50	21
51	21
52	23
53	25
54	23
55	25
56	27
57	17
58	19
59	21
60	23
61	23
62	25
63	27
64	25
65	27
66	29
67	31
68	11
69	13
70	15
71	17
72	17

n	a(n)
1	1
2	3
3	5
4	7
5	7
6	9
7	11
8	9
9	11
10	13
11	15
12	9
13	11
14	13
15	15
16	15
17	11
18	13
19	15
20	17
21	17
22	19
23	13
24	15
25	17
26	19
27	19
28	21
29	23
30	11
31	13
32	15
33	17
34	17
35	19
36	21
37	19
38	13
39	15
40	17
41	19
42	19
43	21
44	23
45	21
46	23
47	15
48	17
49	19
50	21
51	21
52	23
53	25
54	23
55	25
56	27
57	17
58	19
59	21
60	23
61	23
62	25
63	27
64	25
65	27
66	29
67	31
68	11
69	13
70	15
71	17
72	17