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.

A156989 Largest size of a subset of {1,2,3}^n that does not contain any combinatorial lines (i.e., strings formed by 1, 2, 3, and at least one instance of a wildcard x, with x then substituted for 1, 2, or 3, e.g. 12x3x gives the combinatorial line 12131, 12232, 12333.)

Table of values

n a(n)
0 1
1 2
2 6
3 18
4 52
5 150
6 450

List of values

[1, 2, 6, 18, 52, 150, 450]

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

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