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.

A280674 Number of 2 X n 0..2 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.

Table of values

n a(n)
1 2
2 11
3 59
4 338
5 1917
6 10893
7 61880
8 351541
9 1997095
10 11345458
11 64453321
12 366158041
13 2080136592
14 11817214849
15 67133363931
16 381383313234
17 2166631062437
18 12308588230773
19 69924846394792
20 397241669934877
21 2256722073320511

List of values

[2, 11, 59, 338, 1917, 10893, 61880, 351541, 1997095, 11345458, 64453321, 366158041, 2080136592, 11817214849, 67133363931, 381383313234, 2166631062437, 12308588230773, 69924846394792, 397241669934877, 2256722073320511]

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

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