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.

A109895 Group the natural numbers so that every 2n-th group product is divisible by the single number in the next group. (1), (2,3,4,5), (6), (7,8,9,10,11), (12), (13,14,15,16,17,18,19),(20), (21,22,23,24,25,26,27),(28),... Sequence contains the single members of the odd numbered groups.

Table of values

n a(n)
1 1
2 6
3 12
4 20
5 28
6 36
7 45
8 56
9 70
10 80
11 90
12 104
13 112
14 120
15 132
16 140
17 154
18 168
19 180
20 192
21 208
22 220
23 234
24 250
25 264
26 280
27 297
28 312
29 324
30 336
31 350
32 360
33 378
34 396
35 416
36 432
37 448
38 462
39 480
40 495
41 504
42 520
43 539
44 560
45 576
46 594
47 612
48 630
49 640
50 660
51 672
52 693
53 714
54 728
55 748

List of values

[1, 6, 12, 20, 28, 36, 45, 56, 70, 80, 90, 104, 112, 120, 132, 140, 154, 168, 180, 192, 208, 220, 234, 250, 264, 280, 297, 312, 324, 336, 350, 360, 378, 396, 416, 432, 448, 462, 480, 495, 504, 520, 539, 560, 576, 594, 612, 630, 640, 660, 672, 693, 714, 728, 748]

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

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