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.

A249512 Expansion of 1/(1-x*sqrt(4*x^2+1)-2*x^2).

Table of values

n a(n)
0 1
1 1
2 3
3 7
4 15
5 33
6 75
7 169
8 375
9 835
10 1875
11 4203
12 9375
13 20931
14 46875
15 104919
16 234375
17 523737
18 1171875
19 2621545
20 5859375
21 13098001
22 29296875
23 65523597
24 146484375
25 327500413
26 732421875
27 1637918089

List of values

[1, 1, 3, 7, 15, 33, 75, 169, 375, 835, 1875, 4203, 9375, 20931, 46875, 104919, 234375, 523737, 1171875, 2621545, 5859375, 13098001, 29296875, 65523597, 146484375, 327500413, 732421875, 1637918089]