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.

A187982 Number of nondecreasing arrangements of n numbers x(i) in -(n+1)..(n+1) with the sum of sign(x(i))*2^|x(i)| zero.

Table of values

n a(n)
1 0
2 3
3 7
4 22
5 82
6 260
7 912
8 3158
9 10920
10 38385
11 134652
12 474953
13 1680801
14 5960094
15 21192029
16 75492493
17 269409262
18 963003740
19 3447075784
20 12354841859
21 44333177653
22 159250306113
23 572602762173
24 2060689223094
25 7422109110741
26 26752896159623
27 96498088175421
28 348296867524920
29 1257893866073062
30 4545530514677703
31 16434464166065112

List of values

[0, 3, 7, 22, 82, 260, 912, 3158, 10920, 38385, 134652, 474953, 1680801, 5960094, 21192029, 75492493, 269409262, 963003740, 3447075784, 12354841859, 44333177653, 159250306113, 572602762173, 2060689223094, 7422109110741, 26752896159623, 96498088175421, 348296867524920, 1257893866073062, 4545530514677703, 16434464166065112]

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

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