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.

A269620 Number of length-4 0..n arrays with no repeated value differing from the previous repeated value by other than plus two, zero or minus 1.

Table of values

n a(n)
1 15
2 78
3 249
4 612
5 1275
6 2370
7 4053
8 6504
9 9927
10 14550
11 20625
12 28428
13 38259
14 50442
15 65325
16 83280
17 104703
18 130014
19 159657
20 194100
21 233835
22 279378
23 331269
24 390072
25 456375
26 530790
27 613953
28 706524
29 809187
30 922650
31 1047645
32 1184928
33 1335279

List of values

[15, 78, 249, 612, 1275, 2370, 4053, 6504, 9927, 14550, 20625, 28428, 38259, 50442, 65325, 83280, 104703, 130014, 159657, 194100, 233835, 279378, 331269, 390072, 456375, 530790, 613953, 706524, 809187, 922650, 1047645, 1184928, 1335279]

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

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