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 | 2 |
| 2 | 4 |
| 3 | 10 |
| 4 | 29 |
| 5 | 86 |
| 6 | 266 |
| 7 | 844 |
| 8 | 2742 |
| 9 | 9032 |
| 10 | 30202 |
| 11 | 101988 |
| 12 | 347914 |
| 13 | 1195500 |
| 14 | 4138310 |
| 15 | 14405848 |
| 16 | 50428392 |
| 17 | 177321636 |
| 18 | 626250990 |
| 19 | 2219876580 |
| 20 | 7896651847 |
| 21 | 28176271634 |
| 22 | 100830069380 |
| 23 | 361757157484 |
| 24 | 1301092926454 |
| 25 | 4689840961196 |
| 26 | 16940093338162 |
| 27 | 61305930699382 |