A047988 - cp's OEIS frontend

A047988 Start with n and reach 2 by repeatedly either dividing by d where d <= the square root or by adding or subtracting 1. The division steps are free, but adding or subtracting 1 costs 1 point. a(n) is the smallest cost to reach 2.

n	a(n)
2	0
3	1
4	0
5	1
6	1
7	1
8	0
9	1
10	1
11	1
12	0
13	1
14	1
15	1
16	0
17	1
18	1
19	2
20	1
21	1
22	1
23	1
24	0
25	1
26	1
27	1
28	1
29	2
30	1
31	1
32	0
33	1
34	1
35	1
36	0
37	1
38	2
39	1
40	0
41	1
42	1
43	2
44	1
45	1
46	1
47	1
48	0
49	1
50	1
51	1
52	1
53	2
54	1
55	1
56	0
57	1
58	2
59	1
60	0
61	1
62	1
63	1
64	0
65	1
66	1
67	2
68	1
69	1
70	1
71	1
72	0
73	1
74	1
75	1
76	2
77	1
78	1
79	1
80	0
81	1
82	1
83	1
84	0
85	1
86	2
87	2
88	1
89	2
90	1
91	1
92	1
93	1
94	1
95	1
96	0
97	1
98	1
99	1
100	1
101	2

[0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 2, 1, 1, 1, 1, 0, 1, 1, 1, 1, 2, 1, 1, 0, 1, 1, 1, 0, 1, 2, 1, 0, 1, 1, 2, 1, 1, 1, 1, 0, 1, 1, 1, 1, 2, 1, 1, 0, 1, 2, 1, 0, 1, 1, 1, 0, 1, 1, 2, 1, 1, 1, 1, 0, 1, 1, 1, 2, 1, 1, 1, 0, 1, 1, 1, 0, 1, 2, 2, 1, 2, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 2]

cp's OEIS Frontend

A047988 Start with n and reach 2 by repeatedly either dividing by d where d <= the square root or by adding or subtracting 1. The division steps are free, but adding or subtracting 1 costs 1 point. a(n) is the smallest cost to reach 2.

Table of values

List of values

n	a(n)
2	0
3	1
4	0
5	1
6	1
7	1
8	0
9	1
10	1
11	1
12	0
13	1
14	1
15	1
16	0
17	1
18	1
19	2
20	1
21	1
22	1
23	1
24	0
25	1
26	1
27	1
28	1
29	2
30	1
31	1
32	0
33	1
34	1
35	1
36	0
37	1
38	2
39	1
40	0
41	1
42	1
43	2
44	1
45	1
46	1
47	1
48	0
49	1
50	1
51	1
52	1
53	2
54	1
55	1
56	0
57	1
58	2
59	1
60	0
61	1
62	1
63	1
64	0
65	1
66	1
67	2
68	1
69	1
70	1
71	1
72	0
73	1
74	1
75	1
76	2
77	1
78	1
79	1
80	0
81	1
82	1
83	1
84	0
85	1
86	2
87	2
88	1
89	2
90	1
91	1
92	1
93	1
94	1
95	1
96	0
97	1
98	1
99	1
100	1
101	2

n	a(n)
2	0
3	1
4	0
5	1
6	1
7	1
8	0
9	1
10	1
11	1
12	0
13	1
14	1
15	1
16	0
17	1
18	1
19	2
20	1
21	1
22	1
23	1
24	0
25	1
26	1
27	1
28	1
29	2
30	1
31	1
32	0
33	1
34	1
35	1
36	0
37	1
38	2
39	1
40	0
41	1
42	1
43	2
44	1
45	1
46	1
47	1
48	0
49	1
50	1
51	1
52	1
53	2
54	1
55	1
56	0
57	1
58	2
59	1
60	0
61	1
62	1
63	1
64	0
65	1
66	1
67	2
68	1
69	1
70	1
71	1
72	0
73	1
74	1
75	1
76	2
77	1
78	1
79	1
80	0
81	1
82	1
83	1
84	0
85	1
86	2
87	2
88	1
89	2
90	1
91	1
92	1
93	1
94	1
95	1
96	0
97	1
98	1
99	1
100	1
101	2

n	a(n)
2	0
3	1
4	0
5	1
6	1
7	1
8	0
9	1
10	1
11	1
12	0
13	1
14	1
15	1
16	0
17	1
18	1
19	2
20	1
21	1
22	1
23	1
24	0
25	1
26	1
27	1
28	1
29	2
30	1
31	1
32	0
33	1
34	1
35	1
36	0
37	1
38	2
39	1
40	0
41	1
42	1
43	2
44	1
45	1
46	1
47	1
48	0
49	1
50	1
51	1
52	1
53	2
54	1
55	1
56	0
57	1
58	2
59	1
60	0
61	1
62	1
63	1
64	0
65	1
66	1
67	2
68	1
69	1
70	1
71	1
72	0
73	1
74	1
75	1
76	2
77	1
78	1
79	1
80	0
81	1
82	1
83	1
84	0
85	1
86	2
87	2
88	1
89	2
90	1
91	1
92	1
93	1
94	1
95	1
96	0
97	1
98	1
99	1
100	1
101	2