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.

A229441 Number of n X 4 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, and rows and columns lexicographically nondecreasing.

Table of values

n a(n)
1 6
2 14
3 37
4 109
5 324
6 915
7 2402
8 5843
9 13229
10 28071
11 56234
12 107080
13 194989
14 341334
15 576993
16 945488
17 1506848
18 2342300
19 3559899
20 5301215
21 7749202
22 11137381
23 15760476
24 21986649
25 30271487
26 41173901
27 55374104
28 73693842
29 97119059
30 126825184

List of values

[6, 14, 37, 109, 324, 915, 2402, 5843, 13229, 28071, 56234, 107080, 194989, 341334, 576993, 945488, 1506848, 2342300, 3559899, 5301215, 7749202, 11137381, 15760476, 21986649, 30271487, 41173901, 55374104, 73693842, 97119059, 126825184]

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

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