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 | 3 |
| 2 | 11 |
| 3 | 43 |
| 4 | 174 |
| 5 | 721 |
| 6 | 3042 |
| 7 | 13022 |
| 8 | 56420 |
| 9 | 246977 |
| 10 | 1090846 |
| 11 | 4856162 |
| 12 | 21770665 |
| 13 | 98217318 |
| 14 | 445634370 |
| 15 | 2032434475 |
| 16 | 9313305870 |
| 17 | 42861416044 |
| 18 | 198038717055 |
| 19 | 918368326483 |
| 20 | 4273103732070 |
| 21 | 19944292913477 |
| 22 | 93356009312511 |
| 23 | 438150836819153 |