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.

A250421 Number of length 4+1 0..n arrays with the sum of the minimum of each adjacent pair multiplied by some arrangement of +-1 equal to zero.

Table of values

n a(n)
1 20
2 125
3 476
4 1351
5 3154
6 6433
7 11906
8 20461
9 33178
10 51359
11 76520
12 110417
13 155080
14 212797
15 286144
16 378023
17 491638
18 630529
19 798614
20 1000157
21 1239806
22 1522639
23 1854124
24 2240161
25 2687132
26 3201853
27 3791620
28 4464263
29 5228090
30 6091937
31 7065226

List of values

[20, 125, 476, 1351, 3154, 6433, 11906, 20461, 33178, 51359, 76520, 110417, 155080, 212797, 286144, 378023, 491638, 630529, 798614, 1000157, 1239806, 1522639, 1854124, 2240161, 2687132, 3201853, 3791620, 4464263, 5228090, 6091937, 7065226]