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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.

A266734 Number of words on {1,1,2,2,3,3,...,n,n} avoiding the pattern 1234.

Table of values

n a(n)
0 1
1 1
2 6
3 90
4 1879
5 47024
6 1331664
7 41250519
8 1367533365
9 47808569835
10 1744233181074
11 65905305836049
12 2564220925607625
13 102277575120518170
14 4167486279986250932
15 172988069360147449566
16 7298137818882637998561
17 312349784398279829229533
18 13539988681466075755541070

List of values

[1, 1, 6, 90, 1879, 47024, 1331664, 41250519, 1367533365, 47808569835, 1744233181074, 65905305836049, 2564220925607625, 102277575120518170, 4167486279986250932, 172988069360147449566, 7298137818882637998561, 312349784398279829229533, 13539988681466075755541070]

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

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