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.

A267639 Number of nX3 0..1 arrays with every repeated value in every row and column unequal to the previous repeated value, and new values introduced in row-major sequential order.

Table of values

n a(n)
1 3
2 18
3 51
4 189
5 429
6 1353
7 2829
8 8427
9 16899
10 49443
11 96657
12 282717
13 542913
14 1601355
15 3032535
16 9058395
17 16953333
18 51380925
19 95168013
20 292791555
21 537249507
22 1677388467
23 3051796161
24 9662000493
25 17443801617
26 55944191787
27 100303228599

List of values

[3, 18, 51, 189, 429, 1353, 2829, 8427, 16899, 49443, 96657, 282717, 542913, 1601355, 3032535, 9058395, 16953333, 51380925, 95168013, 292791555, 537249507, 1677388467, 3051796161, 9662000493, 17443801617, 55944191787, 100303228599]

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

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