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.

A377207 Number of n-digit numbers where every digit is either a 9 or adjacent to a 9.

Table of values

n a(n)
1 1
2 18
3 99
4 342
5 2691
6 13788
7 65709
8 407772
9 2115981
10 11108358
11 63181719
12 334551402
13 1802963871
14 9931645728
15 53256984129
16 288681869232
17 1572458030361
18 8484410567898
19 46019764248939
20 249748559819262
21 1351163694059451
22 7326501636596868
23 39716608228492149
24 215099382176679492

List of values

[1, 18, 99, 342, 2691, 13788, 65709, 407772, 2115981, 11108358, 63181719, 334551402, 1802963871, 9931645728, 53256984129, 288681869232, 1572458030361, 8484410567898, 46019764248939, 249748559819262, 1351163694059451, 7326501636596868, 39716608228492149, 215099382176679492]

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

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