A291790 - cp's OEIS frontend

A291790 Numbers whose trajectory under iteration of the map k -> (sigma(k)+phi(k))/2 consists only of integers and is unbounded.

n	a(n)
1	270
2	290
3	308
4	326
5	327
6	328
7	352
8	369
9	393
10	394
11	395
12	396
13	410
14	440
15	458
16	459
17	465
18	496
19	504
20	510
21	525
22	559
23	560
24	570
25	606
26	616
27	620
28	685
29	686
30	702
31	712
32	725
33	734
34	735
35	737
36	738
37	745
38	746
39	747
40	783
41	791
42	792
43	805
44	806
45	813
46	814
47	815
48	816
49	828

[270, 290, 308, 326, 327, 328, 352, 369, 393, 394, 395, 396, 410, 440, 458, 459, 465, 496, 504, 510, 525, 559, 560, 570, 606, 616, 620, 685, 686, 702, 712, 725, 734, 735, 737, 738, 745, 746, 747, 783, 791, 792, 805, 806, 813, 814, 815, 816, 828]

cp's OEIS Frontend

A291790 Numbers whose trajectory under iteration of the map k -> (sigma(k)+phi(k))/2 consists only of integers and is unbounded.

Table of values

List of values

n	a(n)
1	270
2	290
3	308
4	326
5	327
6	328
7	352
8	369
9	393
10	394
11	395
12	396
13	410
14	440
15	458
16	459
17	465
18	496
19	504
20	510
21	525
22	559
23	560
24	570
25	606
26	616
27	620
28	685
29	686
30	702
31	712
32	725
33	734
34	735
35	737
36	738
37	745
38	746
39	747
40	783
41	791
42	792
43	805
44	806
45	813
46	814
47	815
48	816
49	828

n	a(n)
1	270
2	290
3	308
4	326
5	327
6	328
7	352
8	369
9	393
10	394
11	395
12	396
13	410
14	440
15	458
16	459
17	465
18	496
19	504
20	510
21	525
22	559
23	560
24	570
25	606
26	616
27	620
28	685
29	686
30	702
31	712
32	725
33	734
34	735
35	737
36	738
37	745
38	746
39	747
40	783
41	791
42	792
43	805
44	806
45	813
46	814
47	815
48	816
49	828

n	a(n)
1	270
2	290
3	308
4	326
5	327
6	328
7	352
8	369
9	393
10	394
11	395
12	396
13	410
14	440
15	458
16	459
17	465
18	496
19	504
20	510
21	525
22	559
23	560
24	570
25	606
26	616
27	620
28	685
29	686
30	702
31	712
32	725
33	734
34	735
35	737
36	738
37	745
38	746
39	747
40	783
41	791
42	792
43	805
44	806
45	813
46	814
47	815
48	816
49	828