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 | 1 |
| 3 | 3 |
| 4 | 11 |
| 5 | 38 |
| 6 | 127 |
| 7 | 423 |
| 8 | 1423 |
| 9 | 4854 |
| 10 | 16787 |
| 11 | 58776 |
| 12 | 208001 |
| 13 | 742888 |
| 14 | 2674427 |
| 15 | 9694831 |
| 16 | 35357655 |
| 17 | 129644774 |
| 18 | 477638683 |
| 19 | 1767263172 |
| 20 | 6564120401 |
| 21 | 24466267000 |
| 22 | 91482563619 |
| 23 | 343059613628 |
| 24 | 1289904147301 |
| 25 | 4861946401428 |
| 26 | 18367353072127 |
| 27 | 69533550915978 |
| 28 | 263747951750333 |
| 29 | 1002242216651340 |
| 30 | 3814986502092275 |