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.

A377657 Array read by ascending antidiagonals: A(n, k) = Sum_{j=0..k} tan(j*Pi/(1 + 2*k))^(2*n).

Table of values

n a(n)
0 1
1 0
2 2
3 0
4 3
5 3
6 0
7 9
8 10
9 4
10 0
11 27
12 90
13 21
14 5
15 0
16 81
17 850
18 371
19 36
20 6
21 0
22 243
23 8050
24 7077
25 1044
26 55
27 7
28 0
29 729
30 76250
31 135779
32 33300
33 2365
34 78
35 8
36 0
37 2187
38 722250
39 2606261
40 1070244
41 113311
42 4654
43 105
44 9
45 0
46 6561
47 6841250
48 50028755
49 34420356
50 5476405
51 312390
52 8295
53 136
54 10

List of values

[1, 0, 2, 0, 3, 3, 0, 9, 10, 4, 0, 27, 90, 21, 5, 0, 81, 850, 371, 36, 6, 0, 243, 8050, 7077, 1044, 55, 7, 0, 729, 76250, 135779, 33300, 2365, 78, 8, 0, 2187, 722250, 2606261, 1070244, 113311, 4654, 105, 9, 0, 6561, 6841250, 50028755, 34420356, 5476405, 312390, 8295, 136, 10]

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

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