cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A195085 Positive integers n for which there exist exactly two integers k in {1,2,3,...,n-1} such that k*n is square.

Table of values

n a(n)
1 9
2 18
3 27
4 45
5 54
6 63
7 90
8 99
9 117
10 126
11 135
12 153
13 171
14 189
15 198
16 207
17 234
18 261
19 270
20 279
21 297
22 306
23 315
24 333
25 342
26 351
27 369
28 378
29 387
30 414
31 423
32 459
33 477
34 495
35 513
36 522
37 531
38 549
39 558
40 585
41 594
42 603
43 621
44 630
45 639
46 657
47 666
48 693
49 702
50 711
51 738
52 747
53 765
54 774
55 783

List of values

[9, 18, 27, 45, 54, 63, 90, 99, 117, 126, 135, 153, 171, 189, 198, 207, 234, 261, 270, 279, 297, 306, 315, 333, 342, 351, 369, 378, 387, 414, 423, 459, 477, 495, 513, 522, 531, 549, 558, 585, 594, 603, 621, 630, 639, 657, 666, 693, 702, 711, 738, 747, 765, 774, 783]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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