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) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 12 |
| 4 | 37 |
| 5 | 118 |
| 6 | 380 |
| 7 | 1229 |
| 8 | 3989 |
| 9 | 12987 |
| 10 | 42394 |
| 11 | 138709 |
| 12 | 454768 |
| 13 | 1493690 |
| 14 | 4913969 |
| 15 | 16189534 |
| 16 | 53407853 |
| 17 | 176397299 |
| 18 | 583242159 |
| 19 | 1930349545 |
| 20 | 6394665589 |
| 21 | 21201345460 |
| 22 | 70346920007 |
| 23 | 233581374587 |
| 24 | 776105485336 |
| 25 | 2580316142887 |
| 26 | 8583746045611 |
| 27 | 28570407158100 |