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 | 15 |
| 3 | 35 |
| 4 | 70 |
| 5 | 127 |
| 6 | 220 |
| 7 | 385 |
| 8 | 715 |
| 9 | 1430 |
| 10 | 3004 |
| 11 | 6385 |
| 12 | 13380 |
| 13 | 27370 |
| 14 | 54740 |
| 15 | 107883 |
| 16 | 211585 |
| 17 | 416405 |
| 18 | 826045 |
| 19 | 1652090 |
| 20 | 3321891 |
| 21 | 6690150 |
| 22 | 13455325 |
| 23 | 26985675 |
| 24 | 53971350 |
| 25 | 107746282 |
| 26 | 214978335 |
| 27 | 429124630 |
| 28 | 857417220 |
| 29 | 1714834440 |
| 30 | 3431847189 |