A189828 - cp's OEIS frontend

A189828 Numbers k for which d(k-1) + d(k+1) is a record, where d(k) is the number of divisors of k.

n	a(n)
1	2
2	3
3	5
4	7
5	11
6	17
7	19
8	29
9	41
10	71
11	161
12	169
13	181
14	239
15	419
16	701
17	721
18	881
19	1079
20	1681
21	2159
22	2519
23	2521
24	4031
25	4159
26	5039
27	7561
28	8399
29	10081
30	13441
31	13859
32	18721
33	20161
34	22679
35	25199
36	27719
37	27721
38	35281
39	45361
40	50399
41	50401
42	55439
43	65519
44	110879
45	138599

[2, 3, 5, 7, 11, 17, 19, 29, 41, 71, 161, 169, 181, 239, 419, 701, 721, 881, 1079, 1681, 2159, 2519, 2521, 4031, 4159, 5039, 7561, 8399, 10081, 13441, 13859, 18721, 20161, 22679, 25199, 27719, 27721, 35281, 45361, 50399, 50401, 55439, 65519, 110879, 138599]

cp's OEIS Frontend

A189828 Numbers k for which d(k-1) + d(k+1) is a record, where d(k) is the number of divisors of k.

Table of values

List of values