The OEIS is supported by the many generous donors to the OEIS Foundation.
Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 12 |
| 4 | 37 |
| 5 | 140 |
| 6 | 454 |
| 7 | 1566 |
| 8 | 5670 |
| 9 | 18738 |
| 10 | 70800 |
| 11 | 263002 |
| 12 | 1065240 |
| 13 | 4146500 |
| 14 | 15269976 |
| 15 | 61593260 |
| 16 | 233206636 |
| 17 | 879932068 |
| 18 | 3442083056 |
| 19 | 12794936028 |
| 20 | 49150133908 |
| 21 | 188187379818 |
| 22 | 690417160564 |
| 23 | 2688772826468 |
| 24 | 10355819787218 |
| 25 | 42350139855568 |
| 26 | 167122149149460 |
[1,1,4,12,37,140,454,1566,5670,18738,70800,263002, 1065240,4146500,15269976,61593260,233206636, 879932068,3442083056,12794936028,49150133908, 188187379818,690417160564,2688772826468, 10355819787218,42350139855568,167122149149460] |