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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.

A317502 Triangle read by rows: T(0,0) = 1; T(n,k) = 3 T(n-1,k) - 2 * T(n-3,k-1) for k = 0..floor(n/3); T(n,k)=0 for n or k < 0.

Table of values

n a(n)
0 1
1 3
2 9
3 27
4 -2
5 81
6 -12
7 243
8 -54
9 729
10 -216
11 4
12 2187
13 -810
14 36
15 6561
16 -2916
17 216
18 19683
19 -10206
20 1080
21 -8
22 59049
23 -34992
24 4860
25 -96
26 177147
27 -118098
28 20412
29 -720
30 531441
31 -393660
32 81648
33 -4320
34 16
35 1594323
36 -1299078
37 314928
38 -22680
39 240
40 4782969
41 -4251528
42 1180980
43 -108864
44 2160

List of values

[1, 3, 9, 27, -2, 81, -12, 243, -54, 729, -216, 4, 2187, -810, 36, 6561, -2916, 216, 19683, -10206, 1080, -8, 59049, -34992, 4860, -96, 177147, -118098, 20412, -720, 531441, -393660, 81648, -4320, 16, 1594323, -1299078, 314928, -22680, 240, 4782969, -4251528, 1180980, -108864, 2160]

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

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