A307023 - cp's OEIS frontend

A307023 Lexicographically earliest sequence starting with a(1) = 1 and a(2) = 2 such that two consecutive terms of opposite parity are followed by their sum; else (same parity), by the smallest term not yet in the sequence.

n	a(n)
1	1
2	2
3	3
4	5
5	4
6	9
7	13
8	6
9	19
10	25
11	7
12	8
13	15
14	23
15	10
16	33
17	43
18	11
19	12
20	23
21	35
22	14
23	49
24	63
25	16
26	79
27	95
28	17
29	18
30	35
31	53
32	20
33	73
34	93
35	21
36	22
37	43
38	65
39	24
40	89
41	113
42	26
43	139
44	165
45	27
46	28
47	55
48	83
49	29
50	30
51	59
52	89
53	31
54	32
55	63
56	95
57	34
58	129
59	163
60	36
61	199
62	235
63	37
64	38
65	75
66	113
67	39
68	40
69	79
70	119
71	41
72	42
73	83
74	125
75	44
76	169
77	213
78	45
79	46
80	91
81	137

[1, 2, 3, 5, 4, 9, 13, 6, 19, 25, 7, 8, 15, 23, 10, 33, 43, 11, 12, 23, 35, 14, 49, 63, 16, 79, 95, 17, 18, 35, 53, 20, 73, 93, 21, 22, 43, 65, 24, 89, 113, 26, 139, 165, 27, 28, 55, 83, 29, 30, 59, 89, 31, 32, 63, 95, 34, 129, 163, 36, 199, 235, 37, 38, 75, 113, 39, 40, 79, 119, 41, 42, 83, 125, 44, 169, 213, 45, 46, 91, 137]

cp's OEIS Frontend

A307023 Lexicographically earliest sequence starting with a(1) = 1 and a(2) = 2 such that two consecutive terms of opposite parity are followed by their sum; else (same parity), by the smallest term not yet in the sequence.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	5
5	4
6	9
7	13
8	6
9	19
10	25
11	7
12	8
13	15
14	23
15	10
16	33
17	43
18	11
19	12
20	23
21	35
22	14
23	49
24	63
25	16
26	79
27	95
28	17
29	18
30	35
31	53
32	20
33	73
34	93
35	21
36	22
37	43
38	65
39	24
40	89
41	113
42	26
43	139
44	165
45	27
46	28
47	55
48	83
49	29
50	30
51	59
52	89
53	31
54	32
55	63
56	95
57	34
58	129
59	163
60	36
61	199
62	235
63	37
64	38
65	75
66	113
67	39
68	40
69	79
70	119
71	41
72	42
73	83
74	125
75	44
76	169
77	213
78	45
79	46
80	91
81	137

n	a(n)
1	1
2	2
3	3
4	5
5	4
6	9
7	13
8	6
9	19
10	25
11	7
12	8
13	15
14	23
15	10
16	33
17	43
18	11
19	12
20	23
21	35
22	14
23	49
24	63
25	16
26	79
27	95
28	17
29	18
30	35
31	53
32	20
33	73
34	93
35	21
36	22
37	43
38	65
39	24
40	89
41	113
42	26
43	139
44	165
45	27
46	28
47	55
48	83
49	29
50	30
51	59
52	89
53	31
54	32
55	63
56	95
57	34
58	129
59	163
60	36
61	199
62	235
63	37
64	38
65	75
66	113
67	39
68	40
69	79
70	119
71	41
72	42
73	83
74	125
75	44
76	169
77	213
78	45
79	46
80	91
81	137

n	a(n)
1	1
2	2
3	3
4	5
5	4
6	9
7	13
8	6
9	19
10	25
11	7
12	8
13	15
14	23
15	10
16	33
17	43
18	11
19	12
20	23
21	35
22	14
23	49
24	63
25	16
26	79
27	95
28	17
29	18
30	35
31	53
32	20
33	73
34	93
35	21
36	22
37	43
38	65
39	24
40	89
41	113
42	26
43	139
44	165
45	27
46	28
47	55
48	83
49	29
50	30
51	59
52	89
53	31
54	32
55	63
56	95
57	34
58	129
59	163
60	36
61	199
62	235
63	37
64	38
65	75
66	113
67	39
68	40
69	79
70	119
71	41
72	42
73	83
74	125
75	44
76	169
77	213
78	45
79	46
80	91
81	137