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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.

A127359 a(n) = Sum_{k=0..n} binomial(n, floor(k/2))*3^(n-k).

Table of values

n a(n)
0 1
1 4
2 14
3 48
4 162
5 544
6 1820
7 6080
8 20290
9 67680
10 225684
11 752448
12 2508468
13 8362176
14 27875064
15 92919168
16 309734850
17 1032458080
18 3441543140
19 11471842880
20 38239537852
21 127465249344
22 424884399624
23 1416281802368
24 4720940242612
25 15736469278144
26 52454901060680

List of values

[1, 4, 14, 48, 162, 544, 1820, 6080, 20290, 67680, 225684, 752448, 2508468, 8362176, 27875064, 92919168, 309734850, 1032458080, 3441543140, 11471842880, 38239537852, 127465249344, 424884399624, 1416281802368, 4720940242612, 15736469278144, 52454901060680]

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

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