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.

A187985 Number of nondecreasing arrangements of n numbers x(i) in -(n+4)..(n+4) with the sum of sign(x(i))*2^|x(i)| zero.

Table of values

n a(n)
1 0
2 6
3 13
4 49
5 181
6 597
7 2166
8 7592
9 26835
10 95590
11 339475
12 1211024
13 4324913
14 15465952
15 55398468
16 198646230
17 713134270
18 2562757415
19 9218114300
20 33185957425
21 119566240848
22 431102833455
23 1555423251527
24 5615525795887
25 20285623430206
26 73320521305274
27 265147098624058
28 959309368316993
29 3472389521265649

List of values

[0, 6, 13, 49, 181, 597, 2166, 7592, 26835, 95590, 339475, 1211024, 4324913, 15465952, 55398468, 198646230, 713134270, 2562757415, 9218114300, 33185957425, 119566240848, 431102833455, 1555423251527, 5615525795887, 20285623430206, 73320521305274, 265147098624058, 959309368316993, 3472389521265649]

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

Content is available under The OEIS End-User License Agreement.