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 | 1 |
| 1 | 3 |
| 2 | 11 |
| 3 | 53 |
| 4 | 261 |
| 5 | 1303 |
| 6 | 6511 |
| 7 | 32553 |
| 8 | 162761 |
| 9 | 813803 |
| 10 | 4069011 |
| 11 | 20345053 |
| 12 | 101725261 |
| 13 | 508626303 |
| 14 | 2543131511 |
| 15 | 12715657553 |
| 16 | 63578287761 |
| 17 | 317891438803 |
| 18 | 1589457194011 |
| 19 | 7947285970053 |
| 20 | 39736429850261 |
| 21 | 198682149251303 |
| 22 | 993410746256511 |
| 23 | 4967053731282553 |