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.

A187979 Number of nondecreasing arrangements of n numbers x(i) in -(2n-2)..(2n-2) with the sum of sign(x(i))*2^|x(i)| zero.

Table of values

n a(n)
1 0
2 2
3 7
4 30
5 144
6 597
7 2742
8 12148
9 54696
10 247482
11 1120330
12 5099759
13 23249035
14 106285418
15 486878283
16 2234333944
17 10271022863
18 47283130811
19 217962771486
20 1005958652638
21 4647869260260
22 21496269109425
23 99510938004788
24 461047642206301
25 2137763442289891
26 9919444208575431
27 46058149007746511
28 213991712768042425
29 994811217776431456
30 4627232005483362687

List of values

[0, 2, 7, 30, 144, 597, 2742, 12148, 54696, 247482, 1120330, 5099759, 23249035, 106285418, 486878283, 2234333944, 10271022863, 47283130811, 217962771486, 1005958652638, 4647869260260, 21496269109425, 99510938004788, 461047642206301, 2137763442289891, 9919444208575431, 46058149007746511, 213991712768042425, 994811217776431456, 4627232005483362687]

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

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