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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.

A201950 Central coefficients in Product_{k=0..n-1} (1 + k*x + x^2).

Table of values

n a(n)
0 1
1 0
2 2
3 6
4 28
5 160
6 1078
7 8358
8 73260
9 716112
10 7721844
11 91039740
12 1164932470
13 16077368580
14 238037983558
15 3763371442530
16 63276351409092
17 1127406030014112
18 21218146474666864
19 420611921077524912
20 8759617763834095796
21 191208185756772875880

List of values

[1, 0, 2, 6, 28, 160, 1078, 8358, 73260, 716112, 7721844, 91039740, 1164932470, 16077368580, 238037983558, 3763371442530, 63276351409092, 1127406030014112, 21218146474666864, 420611921077524912, 8759617763834095796, 191208185756772875880]

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

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