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.

A117381 Expansion of 1/((1-4*x*c(x))(1-x^2*c(x))), c(x) the g.f. of A000108.

Table of values

n a(n)
0 1
1 4
2 21
3 109
4 575
5 3047
6 16192
7 86171
8 458972
9 2445825
10 13037508
11 69509558
12 370634265
13 1976421031
14 10539858413
15 56208784808
16 299766435277
17 1598704176149
18 8526238418811
19 45472594256564
20 242517996824355

List of values

[1, 4, 21, 109, 575, 3047, 16192, 86171, 458972, 2445825, 13037508, 69509558, 370634265, 1976421031, 10539858413, 56208784808, 299766435277, 1598704176149, 8526238418811, 45472594256564, 242517996824355]

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

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