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.

A151281 Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, 0), (1, 0), (1, 1)}.

Table of values

n a(n)
0 1
1 2
2 6
3 16
4 48
5 136
6 408
7 1184
8 3552
9 10432
10 31296
11 92544
12 277632
13 824448
14 2473344
15 7365120
16 22095360
17 65920000
18 197760000
19 590790656
20 1772371968
21 5299916800
22 15899750400
23 47578857472
24 142736572416
25 427357700096
26 1282073100288
27 3840133464064
28 11520400392192
29 34517383151616
30 103552149454848

List of values

[1, 2, 6, 16, 48, 136, 408, 1184, 3552, 10432, 31296, 92544, 277632, 824448, 2473344, 7365120, 22095360, 65920000, 197760000, 590790656, 1772371968, 5299916800, 15899750400, 47578857472, 142736572416, 427357700096, 1282073100288, 3840133464064, 11520400392192, 34517383151616, 103552149454848]

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

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