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.

A364685 The number of binary sequences of length n for which all patterns {0,1},{0,0},{1,0},{1,1} appear for the first time. In particular, three of the patterns will have appeared at least once before the (n-1)st digit in the sequence and the remaining pattern appears for the first and only time at positions {n-1,n} in the sequence.

Table of values

n a(n)
5 4
6 10
7 18
8 30
9 48
10 76
11 120
12 190
13 302
14 482
15 772
16 1240
17 1996
18 3218
19 5194
20 8390
21 13560
22 21924
23 35456
24 57350
25 92774
26 150090
27 242828
28 392880
29 635668
30 1028506
31 1664130
32 2692590
33 4356672
34 7049212
35 11405832
36 18454990
37 29860766
38 48315698
39 78176404
40 126492040
41 204668380

List of values

[4, 10, 18, 30, 48, 76, 120, 190, 302, 482, 772, 1240, 1996, 3218, 5194, 8390, 13560, 21924, 35456, 57350, 92774, 150090, 242828, 392880, 635668, 1028506, 1664130, 2692590, 4356672, 7049212, 11405832, 18454990, 29860766, 48315698, 78176404, 126492040, 204668380]

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

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