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 | 2 |
| 3 | 5 |
| 4 | 10 |
| 5 | 257 |
| 6 | 38 |
| 7 | 46657 |
| 8 | 16394 |
| 9 | 1679621 |
| 10 | 262402 |
| 11 | 10000000001 |
| 12 | 4194350 |
| 13 | 8916100448257 |
| 14 | 13060740674 |
| 15 | 4398046511365 |
| 16 | 35184372105226 |
| 17 | 18446744073709551617 |
| 18 | 16926661124390 |
| 19 | 39346408075296537575425 |
| 20 | 144115188076118282 |
| 21 | 3833759992447475168837 |