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.

A200051 Number of -2..2 arrays x(0..n-1) of n elements with zero sum and elements alternately strictly increasing and strictly decreasing.

Table of values

n a(n)
1 1
2 4
3 10
4 26
5 68
6 178
7 472
8 1276
9 3462
10 9496
11 26024
12 71956
13 198740
14 552814
15 1535556
16 4290252
17 11968194
18 33553214
19 93917400
20 264020106
21 741024426
22 2087799972
23 5872999754
24 16577458520
25 46720454112
26 132081262316
27 372843051320

List of values

[1, 4, 10, 26, 68, 178, 472, 1276, 3462, 9496, 26024, 71956, 198740, 552814, 1535556, 4290252, 11968194, 33553214, 93917400, 264020106, 741024426, 2087799972, 5872999754, 16577458520, 46720454112, 132081262316, 372843051320]

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

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