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.

A080227 a(n) = n*a(n-1) + (1/2)*(1+(-1)^n), a(0)=0.

Table of values

n a(n)
0 0
1 0
2 1
3 3
4 13
5 65
6 391
7 2737
8 21897
9 197073
10 1970731
11 21678041
12 260136493
13 3381774409
14 47344841727
15 710172625905
16 11362762014481
17 193166954246177
18 3477005176431187
19 66063098352192553
20 1321261967043851061
21 27746501307920872281
22 610423028774259190183

List of values

[0, 0, 1, 3, 13, 65, 391, 2737, 21897, 197073, 1970731, 21678041, 260136493, 3381774409, 47344841727, 710172625905, 11362762014481, 193166954246177, 3477005176431187, 66063098352192553, 1321261967043851061, 27746501307920872281, 610423028774259190183]