A352331 - cp's OEIS frontend

A352331 Numbers k for which phi(k) = phi(k''), where phi is the Euler totient function (A000010) and k'' the second arithmetic derivative of k (A068346).

n	a(n)
1	4
2	27
3	104
4	260
5	296
6	405
7	525
8	740
9	910
10	945
11	1460
12	1806
13	1818
14	2504
15	3125
16	3140
17	3176
18	3656
19	3860
20	4563
21	5540
22	6056
23	6930
24	7016
25	8420
26	8636
27	9224
28	10820
29	12573
30	13256
31	14024
32	15140
33	15464
34	15944
35	16136
36	19940
37	20456
38	21690
39	21860
40	22856
41	23336
42	24020
43	24260

[4, 27, 104, 260, 296, 405, 525, 740, 910, 945, 1460, 1806, 1818, 2504, 3125, 3140, 3176, 3656, 3860, 4563, 5540, 6056, 6930, 7016, 8420, 8636, 9224, 10820, 12573, 13256, 14024, 15140, 15464, 15944, 16136, 19940, 20456, 21690, 21860, 22856, 23336, 24020, 24260]

cp's OEIS Frontend

A352331 Numbers k for which phi(k) = phi(k''), where phi is the Euler totient function (A000010) and k'' the second arithmetic derivative of k (A068346).

Table of values

List of values