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.

A331780 One-half of the number of lines through at least 2 points of an n X n grid of points.

Table of values

n a(n)
0 0
1 0
2 3
3 10
4 31
5 70
6 153
7 268
8 469
9 746
10 1153
11 1648
12 2361
13 3230
14 4415
15 5784
16 7473
17 9450
18 11963
19 14772
20 18255
21 22194
22 26793
23 31824
24 37837
25 44474
26 52187
27 60516
28 69983
29 80318
30 92233
31 104972
32 119525
33 135294
34 152739
35 171240
36 191685
37 213510
38 237915
39 263640

List of values

[0, 0, 3, 10, 31, 70, 153, 268, 469, 746, 1153, 1648, 2361, 3230, 4415, 5784, 7473, 9450, 11963, 14772, 18255, 22194, 26793, 31824, 37837, 44474, 52187, 60516, 69983, 80318, 92233, 104972, 119525, 135294, 152739, 171240, 191685, 213510, 237915, 263640]

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

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