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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.

A229042 Series reversion of (sqrt(1+4*x) - 1)/2 - x^2.

Table of values

n a(n)
1 1
2 2
3 6
4 25
5 114
6 560
7 2880
8 15321
9 83600
10 465322
11 2631668
12 15079922
13 87362184
14 510837760
15 3010987912
16 17870854206
17 106713713826
18 640659094566
19 3864643224900
20 23412690485800
21 142386465217920
22 868967571732540
23 5320093500153120
24 32666064906596550
25 201109232686971492

List of values

[1, 2, 6, 25, 114, 560, 2880, 15321, 83600, 465322, 2631668, 15079922, 87362184, 510837760, 3010987912, 17870854206, 106713713826, 640659094566, 3864643224900, 23412690485800, 142386465217920, 868967571732540, 5320093500153120, 32666064906596550, 201109232686971492]

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

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