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.

A027273 a(n) = Sum_{k=0..2n-1} T(n,k) * T(n,k+1), with T given by A026552.

Table of values

n a(n)
1 2
2 16
3 52
4 428
5 1516
6 12792
7 46936
8 402164
9 1504432
10 13015480
11 49288856
12 429204354
13 1639174304
14 14340670000
15 55108565584
16 483825847108
17 1868067054968
18 16445659005424
19 63734526307552
20 562323306397388
21 2185849699156352
22 19320211642880176
23 75288454939134992

List of values

[2, 16, 52, 428, 1516, 12792, 46936, 402164, 1504432, 13015480, 49288856, 429204354, 1639174304, 14340670000, 55108565584, 483825847108, 1868067054968, 16445659005424, 63734526307552, 562323306397388, 2185849699156352, 19320211642880176, 75288454939134992]