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 | 4 |
| 2 | 42 |
| 3 | 429 |
| 4 | 4244 |
| 5 | 41815 |
| 6 | 413436 |
| 7 | 4102567 |
| 8 | 40775008 |
| 9 | 405774711 |
| 10 | 4042049770 |
| 11 | 40293025322 |
| 12 | 401878286460 |
| 13 | 4009949122673 |
| 14 | 40024266995482 |
| 15 | 399594430078005 |
| 16 | 3990300329780096 |
| 17 | 39853419882545236 |
| 18 | 398095148341559286 |
| 19 | 3977036546783471193 |