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.

A263899 Number of length n arrays of permutations of 0..n-1 with each element moved by -2 to 2 places and the total absolute value of displacements not greater than 2*(n-1).

Table of values

n a(n)
1 1
2 2
3 6
4 13
5 31
6 73
7 172
8 399
9 932
10 2177
11 5081
12 11853
13 27662
14 64554
15 150639
16 351520
17 820296
18 1914208
19 4466904
20 10423760
21 24324417
22 56762346
23 132458006
24 309097941
25 721296815
26 1683185225
27 3927803988
28 9165743599
29 21388759708
30 49911830577

List of values

[1, 2, 6, 13, 31, 73, 172, 399, 932, 2177, 5081, 11853, 27662, 64554, 150639, 351520, 820296, 1914208, 4466904, 10423760, 24324417, 56762346, 132458006, 309097941, 721296815, 1683185225, 3927803988, 9165743599, 21388759708, 49911830577]