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.

A213121 Number of binary arrays of length 2*n+3 with fewer than n ones in any length 2n subsequence (=less than 50% duty cycle).

Table of values

n a(n)
1 1
2 14
3 86
4 424
5 1926
6 8404
7 35836
8 150604
9 626726
10 2589844
11 10646676
12 43594464
13 177950236
14 724578824
15 2944375096
16 11944652884
17 48388816486
18 195794585044
19 791434666276
20 3196307541904
21 12898839944116
22 52019043912664

List of values

[1, 14, 86, 424, 1926, 8404, 35836, 150604, 626726, 2589844, 10646676, 43594464, 177950236, 724578824, 2944375096, 11944652884, 48388816486, 195794585044, 791434666276, 3196307541904, 12898839944116, 52019043912664]

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

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