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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.

A131112 T(n,k) = 4*binomial(n,k) - 3*I(n,k), where I is the identity matrix; triangle T read by rows (n >= 0 and 0 <= k <= n).

Table of values

n a(n)
0 1
1 4
2 1
3 4
4 8
5 1
6 4
7 12
8 12
9 1
10 4
11 16
12 24
13 16
14 1
15 4
16 20
17 40
18 40
19 20
20 1
21 4
22 24
23 60
24 80
25 60
26 24
27 1
28 4
29 28
30 84
31 140
32 140
33 84
34 28
35 1
36 4
37 32
38 112
39 224
40 280
41 224
42 112
43 32
44 1
45 4
46 36
47 144
48 336
49 504
50 504
51 336
52 144
53 36
54 1

List of values

[1, 4, 1, 4, 8, 1, 4, 12, 12, 1, 4, 16, 24, 16, 1, 4, 20, 40, 40, 20, 1, 4, 24, 60, 80, 60, 24, 1, 4, 28, 84, 140, 140, 84, 28, 1, 4, 32, 112, 224, 280, 224, 112, 32, 1, 4, 36, 144, 336, 504, 504, 336, 144, 36, 1]

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

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