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.

A099783 a(n) = Sum_{k=0..floor(n/3)} C(n-k,2*k)*3^(n-2*k).

Table of values

n a(n)
0 1
1 3
2 9
3 30
4 108
5 405
6 1548
7 5967
8 23085
9 89451
10 346842
11 1345248
12 5218263
13 20242872
14 78528609
15 304640595
16 1181814705
17 4584708702
18 17785841652
19 68998115709
20 267670245492
21 1038395956527
22 4028337876861
23 15627474388899
24 60624993311226

List of values

[1, 3, 9, 30, 108, 405, 1548, 5967, 23085, 89451, 346842, 1345248, 5218263, 20242872, 78528609, 304640595, 1181814705, 4584708702, 17785841652, 68998115709, 267670245492, 1038395956527, 4028337876861, 15627474388899, 60624993311226]

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

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