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 | 61 |
| 2 | 1830 |
| 3 | 35990 |
| 4 | 521855 |
| 5 | 5949147 |
| 6 | 55525372 |
| 7 | 436270780 |
| 8 | 2944827765 |
| 9 | 17341763505 |
| 10 | 90177170226 |
| 11 | 418094152866 |
| 12 | 1742058970275 |
| 13 | 6566222272575 |
| 14 | 22512762077400 |
| 15 | 70539987842520 |
| 16 | 202802465047245 |
| 17 | 536830054536825 |
| 18 | 1312251244423350 |
| 19 | 2969831763694950 |