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.

A318637 Expansion of Sum_{n>=1} ( (2 + x^n)^n - 2^n ).

Table of values

n a(n)
1 1
2 4
3 12
4 33
5 80
6 198
7 448
8 1048
9 2305
10 5200
11 11264
12 24824
13 53248
14 115360
15 245800
16 526081
17 1114112
18 2364064
19 4980736
20 10497290
21 22020656
22 46165504
23 96468992
24 201396028
25 419430401
26 872574976
27 1811944704
28 3758469400
29 7784628224
30 16107002892
31 33285996544
32 68721443936
33 141733963008
34 292062232576
35 601295421524
36 1236960724929
37 2542620639232
38 5222702645248
39 10720238663680
40 21990282376768

List of values

[1, 4, 12, 33, 80, 198, 448, 1048, 2305, 5200, 11264, 24824, 53248, 115360, 245800, 526081, 1114112, 2364064, 4980736, 10497290, 22020656, 46165504, 96468992, 201396028, 419430401, 872574976, 1811944704, 3758469400, 7784628224, 16107002892, 33285996544, 68721443936, 141733963008, 292062232576, 601295421524, 1236960724929, 2542620639232, 5222702645248, 10720238663680, 21990282376768]

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

Content is available under The OEIS End-User License Agreement.