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.

A373276 a(n) = Sum_{d|n} (-1)^(d-1) * 3^(n/d-1).

Table of values

n a(n)
1 1
2 2
3 10
4 23
5 82
6 236
7 730
8 2156
9 6571
10 19604
11 59050
12 176918
13 531442
14 1593596
15 4783060
16 14346689
17 43046722
18 129133838
19 387420490
20 1162241726
21 3486785140
22 10460294156
23 31381059610
24 94143003584
25 282429536563
26 847288078004
27 2541865834900
28 7625595889958

List of values

[1, 2, 10, 23, 82, 236, 730, 2156, 6571, 19604, 59050, 176918, 531442, 1593596, 4783060, 14346689, 43046722, 129133838, 387420490, 1162241726, 3486785140, 10460294156, 31381059610, 94143003584, 282429536563, 847288078004, 2541865834900, 7625595889958]