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.

A183821 1/256 the number of (n+1) X 3 0..3 arrays with no 2 X 2 subblock being a reflection across the shared element pair of any horizontal or vertical neighbor.

Table of values

n a(n)
1 15
2 813
3 43947
4 2377341
5 128578815
6 6954559893
7 376152548283
8 20345104031589
9 1100412240703119
10 59518368554767389
11 3219189893127084843
12 174117402720326269485
13 9417546276713264441151
14 509369980225226329837125

List of values

[15, 813, 43947, 2377341, 128578815, 6954559893, 376152548283, 20345104031589, 1100412240703119, 59518368554767389, 3219189893127084843, 174117402720326269485, 9417546276713264441151, 509369980225226329837125]

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

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