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 | 0 |
| 1 | 1 |
| 2 | 5 |
| 3 | 15 |
| 4 | 43 |
| 5 | 119 |
| 6 | 327 |
| 7 | 895 |
| 8 | 2447 |
| 9 | 6687 |
| 10 | 18271 |
| 11 | 49919 |
| 12 | 136383 |
| 13 | 372607 |
| 14 | 1017983 |
| 15 | 2781183 |
| 16 | 7598335 |
| 17 | 20759039 |
| 18 | 56714751 |
| 19 | 154947583 |
| 20 | 423324671 |
| 21 | 1156544511 |
| 22 | 3159738367 |
| 23 | 8632565759 |
| 24 | 23584608255 |
| 25 | 64434348031 |
| 26 | 176037912575 |
| 27 | 480944521215 |
| 28 | 1313964867583 |
| 29 | 3589818777599 |
| 30 | 9807567290367 |