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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.

A203613 For any number n take the polynomial formed by the product of the terms (x-pi), where pi’s are the prime factors of n. Then calculate the area between the minimum and the maximum value of the prime factors. This sequence lists the numbers for which the area is a negative integer.

Table of values

n a(n)
1 55
2 85
3 91
4 115
5 133
6 145
7 187
8 195
9 204
10 205
11 217
12 235
13 247
14 253
15 259
16 265
17 275
18 285
19 295
20 301
21 319
22 351
23 355
24 357
25 385
26 391
27 403
28 415
29 425
30 427
31 445
32 451
33 465
34 469
35 476
36 481
37 483
38 493
39 505
40 511
41 517
42 535
43 553
44 555
45 559
46 565
47 575
48 583
49 589
50 595
51 609
52 621
53 637

List of values

[55, 85, 91, 115, 133, 145, 187, 195, 204, 205, 217, 235, 247, 253, 259, 265, 275, 285, 295, 301, 319, 351, 355, 357, 385, 391, 403, 415, 425, 427, 445, 451, 465, 469, 476, 481, 483, 493, 505, 511, 517, 535, 553, 555, 559, 565, 575, 583, 589, 595, 609, 621, 637]

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

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