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.

A340687 The number of edges on a concave circular triangle formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.

Table of values

n a(n)
1 3
2 21
3 51
4 177
5 354
6 852
7 1686
8 3036
9 5994
10 8550
11 12933
12 16938
13 24303
14 30192
15 41616
16 52581
17 66600
18 82857
19 101199
20 128409
21 153669
22 194505
23 227193
24 271635
25 320898
26 368703
27 431640
28 490884
29 578805
30 646869
31 744717
32 851214
33 943068
34 1071741
35 1195638
36 1367913
37 1523694
38 1713300
39 1885389
40 2082696

List of values

[3, 21, 51, 177, 354, 852, 1686, 3036, 5994, 8550, 12933, 16938, 24303, 30192, 41616, 52581, 66600, 82857, 101199, 128409, 153669, 194505, 227193, 271635, 320898, 368703, 431640, 490884, 578805, 646869, 744717, 851214, 943068, 1071741, 1195638, 1367913, 1523694, 1713300, 1885389, 2082696]

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

Content is available under The OEIS End-User License Agreement.