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.

A194275 Concentric pentagonal numbers of the second kind: a(n) = floor(5*n*(n+1)/6).

Table of values

n a(n)
0 0
1 1
2 5
3 10
4 16
5 25
6 35
7 46
8 60
9 75
10 91
11 110
12 130
13 151
14 175
15 200
16 226
17 255
18 285
19 316
20 350
21 385
22 421
23 460
24 500
25 541
26 585
27 630
28 676
29 725
30 775
31 826
32 880
33 935
34 991
35 1050
36 1110
37 1171
38 1235
39 1300
40 1366
41 1435
42 1505
43 1576
44 1650
45 1725
46 1801
47 1880
48 1960
49 2041
50 2125

List of values

[0, 1, 5, 10, 16, 25, 35, 46, 60, 75, 91, 110, 130, 151, 175, 200, 226, 255, 285, 316, 350, 385, 421, 460, 500, 541, 585, 630, 676, 725, 775, 826, 880, 935, 991, 1050, 1110, 1171, 1235, 1300, 1366, 1435, 1505, 1576, 1650, 1725, 1801, 1880, 1960, 2041, 2125]

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

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