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.

A216212 Number of n step walks (each step +-1 starting from 0) which are never more than 4 or less than -4.

Table of values

n a(n)
0 1
1 2
2 4
3 8
4 16
5 30
6 60
7 110
8 220
9 400
10 800
11 1450
12 2900
13 5250
14 10500
15 19000
16 38000
17 68750
18 137500
19 248750
20 497500
21 900000
22 1800000
23 3256250
24 6512500
25 11781250
26 23562500
27 42625000
28 85250000
29 154218750
30 308437500
31 557968750
32 1115937500
33 2018750000
34 4037500000

List of values

[1, 2, 4, 8, 16, 30, 60, 110, 220, 400, 800, 1450, 2900, 5250, 10500, 19000, 38000, 68750, 137500, 248750, 497500, 900000, 1800000, 3256250, 6512500, 11781250, 23562500, 42625000, 85250000, 154218750, 308437500, 557968750, 1115937500, 2018750000, 4037500000]

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

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