A340612 - cp's OEIS frontend

A340612 a(0) = 0; for n > 0, if n appears in the sequence then a(n) = lastindex(n), where lastindex(n) is the index of the last appearance of n. Otherwise a(n) = a(n-1) - n if nonnegative and not already in the sequence, otherwise a(n) = a(n-1) + n.

n	a(n)
0	0
1	1
2	3
3	2
4	6
5	11
6	4
7	11
8	19
9	10
10	9
11	7
12	19
13	32
14	18
15	33
16	17
17	16
18	14
19	12
20	32
21	53
22	31
23	8
24	32
25	57
26	83
27	56
28	28
29	57
30	27
31	22
32	24
33	15
34	49
35	84
36	48
37	85
38	47
39	86
40	46
41	5
42	47
43	90
44	134
45	89
46	40
47	42
48	36
49	34
50	84
51	135
52	187
53	21
54	75
55	20
56	27
57	29
58	87
59	146
60	206
61	145
62	207
63	144
64	80
65	145
66	79
67	146
68	78
69	147
70	77
71	148
72	76
73	149

[0, 1, 3, 2, 6, 11, 4, 11, 19, 10, 9, 7, 19, 32, 18, 33, 17, 16, 14, 12, 32, 53, 31, 8, 32, 57, 83, 56, 28, 57, 27, 22, 24, 15, 49, 84, 48, 85, 47, 86, 46, 5, 47, 90, 134, 89, 40, 42, 36, 34, 84, 135, 187, 21, 75, 20, 27, 29, 87, 146, 206, 145, 207, 144, 80, 145, 79, 146, 78, 147, 77, 148, 76, 149]

cp's OEIS Frontend

A340612 a(0) = 0; for n > 0, if n appears in the sequence then a(n) = lastindex(n), where lastindex(n) is the index of the last appearance of n. Otherwise a(n) = a(n-1) - n if nonnegative and not already in the sequence, otherwise a(n) = a(n-1) + n.

Table of values

List of values

n	a(n)
0	0
1	1
2	3
3	2
4	6
5	11
6	4
7	11
8	19
9	10
10	9
11	7
12	19
13	32
14	18
15	33
16	17
17	16
18	14
19	12
20	32
21	53
22	31
23	8
24	32
25	57
26	83
27	56
28	28
29	57
30	27
31	22
32	24
33	15
34	49
35	84
36	48
37	85
38	47
39	86
40	46
41	5
42	47
43	90
44	134
45	89
46	40
47	42
48	36
49	34
50	84
51	135
52	187
53	21
54	75
55	20
56	27
57	29
58	87
59	146
60	206
61	145
62	207
63	144
64	80
65	145
66	79
67	146
68	78
69	147
70	77
71	148
72	76
73	149

n	a(n)
0	0
1	1
2	3
3	2
4	6
5	11
6	4
7	11
8	19
9	10
10	9
11	7
12	19
13	32
14	18
15	33
16	17
17	16
18	14
19	12
20	32
21	53
22	31
23	8
24	32
25	57
26	83
27	56
28	28
29	57
30	27
31	22
32	24
33	15
34	49
35	84
36	48
37	85
38	47
39	86
40	46
41	5
42	47
43	90
44	134
45	89
46	40
47	42
48	36
49	34
50	84
51	135
52	187
53	21
54	75
55	20
56	27
57	29
58	87
59	146
60	206
61	145
62	207
63	144
64	80
65	145
66	79
67	146
68	78
69	147
70	77
71	148
72	76
73	149

n	a(n)
0	0
1	1
2	3
3	2
4	6
5	11
6	4
7	11
8	19
9	10
10	9
11	7
12	19
13	32
14	18
15	33
16	17
17	16
18	14
19	12
20	32
21	53
22	31
23	8
24	32
25	57
26	83
27	56
28	28
29	57
30	27
31	22
32	24
33	15
34	49
35	84
36	48
37	85
38	47
39	86
40	46
41	5
42	47
43	90
44	134
45	89
46	40
47	42
48	36
49	34
50	84
51	135
52	187
53	21
54	75
55	20
56	27
57	29
58	87
59	146
60	206
61	145
62	207
63	144
64	80
65	145
66	79
67	146
68	78
69	147
70	77
71	148
72	76
73	149