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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.

A360309 a(n) = Sum_{k=0..floor(n/3)} binomial(n-1-2*k,n-3*k) * binomial(2*k,k).

Table of values

n a(n)
0 1
1 0
2 0
3 2
4 2
5 2
6 8
7 14
8 20
9 46
10 92
11 158
12 314
13 630
14 1176
15 2274
16 4498
17 8674
18 16804
19 32990
20 64358
21 125414
22 245832
23 481674
24 942912
25 1850122
26 3633220
27 7133730
28 14020694
29 27578954
30 54261912
31 106819006
32 210411028
33 414619486
34 817344908
35 1611978734
36 3180333830
37 6276743430

List of values

[1, 0, 0, 2, 2, 2, 8, 14, 20, 46, 92, 158, 314, 630, 1176, 2274, 4498, 8674, 16804, 32990, 64358, 125414, 245832, 481674, 942912, 1850122, 3633220, 7133730, 14020694, 27578954, 54261912, 106819006, 210411028, 414619486, 817344908, 1611978734, 3180333830, 6276743430]

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

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