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.
| n | a(n) |
|---|---|
| 0 | 25 |
| 1 | 145 |
| 2 | 385 |
| 3 | 865 |
| 4 | 1825 |
| 5 | 3745 |
| 6 | 7585 |
| 7 | 15265 |
| 8 | 30625 |
| 9 | 61345 |
| 10 | 122785 |
| 11 | 245665 |
| 12 | 491425 |
| 13 | 982945 |
| 14 | 1965985 |
| 15 | 3932065 |
| 16 | 7864225 |
| 17 | 15728545 |
| 18 | 31457185 |
| 19 | 62914465 |
| 20 | 125829025 |
| 21 | 251658145 |
| 22 | 503316385 |
| 23 | 1006632865 |
| 24 | 2013265825 |
| 25 | 4026531745 |
| 26 | 8053063585 |
| 27 | 16106127265 |
| 28 | 32212254625 |
| 29 | 64424509345 |
| 30 | 128849018785 |