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.

A210371 Number of 2 X 2 matrices with all elements in {0,1,...,n} and nonnegative even determinant.

Table of values

n a(n)
0 1
1 10
2 48
3 112
4 285
5 490
6 968
7 1448
8 2465
9 3410
10 5280
11 6904
12 10021
13 12610
14 17400
15 21312
16 28321
17 33866
18 43704
19 51336
20 64661
21 74898
22 92416
23 105680
24 128297
25 145234
26 173712
27 194928
28 230333
29 256410
30 299776

List of values

[1, 10, 48, 112, 285, 490, 968, 1448, 2465, 3410, 5280, 6904, 10021, 12610, 17400, 21312, 28321, 33866, 43704, 51336, 64661, 74898, 92416, 105680, 128297, 145234, 173712, 194928, 230333, 256410, 299776]