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.

A206857 Number of n X 2 0..2 arrays avoiding the pattern z z+1 z in any row, column, diagonal or antidiagonal.

Table of values

n a(n)
1 9
2 81
3 625
4 4761
5 36481
6 279841
7 2146225
8 16459249
9 126225225
10 968018769
11 7423717921
12 56932346025
13 436613028289
14 3348376640449
15 25678633973281
16 196928934060769
17 1510244084935881
18 11582031898782801
19 88822372650180625

List of values

[9, 81, 625, 4761, 36481, 279841, 2146225, 16459249, 126225225, 968018769, 7423717921, 56932346025, 436613028289, 3348376640449, 25678633973281, 196928934060769, 1510244084935881, 11582031898782801, 88822372650180625]