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.

A190020 Number of obtuse triangles on an n X n grid (or geoboard).

Table of values

n a(n)
1 0
2 0
3 24
4 236
5 1148
6 3932
7 10760
8 25392
9 53576
10 103824
11 188104
12 322852
13 529116
14 835028
15 1275360
16 1893496
17 2742208
18 3886568
19 5402448
20 7381316
21 9928860
22 13168484
23 17243896
24 22319864
25 28579720
26 36237928
27 45532720
28 56732668

List of values

[0, 0, 24, 236, 1148, 3932, 10760, 25392, 53576, 103824, 188104, 322852, 529116, 835028, 1275360, 1893496, 2742208, 3886568, 5402448, 7381316, 9928860, 13168484, 17243896, 22319864, 28579720, 36237928, 45532720, 56732668]