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 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 28 |
| 5 | 93 |
| 6 | 317 |
| 7 | 1090 |
| 8 | 3876 |
| 9 | 13995 |
| 10 | 51182 |
| 11 | 189606 |
| 12 | 709218 |
| 13 | 2675230 |
| 14 | 10166639 |
| 15 | 38883721 |
| 16 | 149559230 |
| 17 | 578153160 |
| 18 | 2245017535 |
| 19 | 8752828951 |
| 20 | 34250020397 |
| 21 | 134465596581 |
| 22 | 529509173245 |
| 23 | 2090920335200 |
| 24 | 8277633788511 |
| 25 | 32846871639751 |
| 26 | 130624556118075 |
| 27 | 520512049658200 |