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.

A084775 a(n) = sum of absolute valued coefficients of (1+x-4*x^2)^n.

Table of values

n a(n)
0 1
1 6
2 34
3 184
4 956
5 4776
6 22986
7 118304
8 624634
9 3281346
10 17687330
11 92606914
12 470392898
13 2348031430
14 11932314170
15 62345998488
16 326780375778
17 1691296908076
18 8780141027670
19 45168987187058
20 230213109996786

List of values

[1, 6, 34, 184, 956, 4776, 22986, 118304, 624634, 3281346, 17687330, 92606914, 470392898, 2348031430, 11932314170, 62345998488, 326780375778, 1691296908076, 8780141027670, 45168987187058, 230213109996786]

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

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