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 | 5 |
| 2 | 33 |
| 3 | 253 |
| 4 | 2073 |
| 5 | 17577 |
| 6 | 152173 |
| 7 | 1336213 |
| 8 | 11854513 |
| 9 | 105997793 |
| 10 | 953658321 |
| 11 | 8622997453 |
| 12 | 78291531921 |
| 13 | 713305091521 |
| 14 | 6518037055321 |
| 15 | 59712126248041 |
| 16 | 548239063327621 |
| 17 | 5043390644753269 |
| 18 | 46475480410336709 |
| 19 | 428936432074181109 |
| 20 | 3964252574286355429 |