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.

A117863 Number of palindromes (in base 4) below 4^n.

Table of values

n a(n)
1 3
2 6
3 18
4 30
5 78
6 126
7 318
8 510
9 1278
10 2046
11 5118
12 8190
13 20478
14 32766
15 81918
16 131070
17 327678
18 524286
19 1310718
20 2097150
21 5242878
22 8388606
23 20971518
24 33554430
25 83886078
26 134217726
27 335544318
28 536870910
29 1342177278
30 2147483646
31 5368709118
32 8589934590

List of values

[3, 6, 18, 30, 78, 126, 318, 510, 1278, 2046, 5118, 8190, 20478, 32766, 81918, 131070, 327678, 524286, 1310718, 2097150, 5242878, 8388606, 20971518, 33554430, 83886078, 134217726, 335544318, 536870910, 1342177278, 2147483646, 5368709118, 8589934590]