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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.

A378070 a(n) = binomial(n - 1, ceiling(n/2)) * binomial(n - 1, ceiling(n/2) - 1).

Table of values

n a(n)
0 1
1 0
2 1
3 2
4 9
5 24
6 100
7 300
8 1225
9 3920
10 15876
11 52920
12 213444
13 731808
14 2944656
15 10306296
16 41409225
17 147232800
18 590976100
19 2127513960
20 8533694884
21 31031617760
22 124408576656
23 456164781072
24 1828114918084
25 6749962774464
26 27043120090000
27 100445874620000
28 402335398890000

List of values

[1, 0, 1, 2, 9, 24, 100, 300, 1225, 3920, 15876, 52920, 213444, 731808, 2944656, 10306296, 41409225, 147232800, 590976100, 2127513960, 8533694884, 31031617760, 124408576656, 456164781072, 1828114918084, 6749962774464, 27043120090000, 100445874620000, 402335398890000]

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

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