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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 6 |
| 4 | 1 |
| 5 | 15 |
| 6 | 90 |
| 7 | 1 |
| 8 | 28 |
| 9 | 70 |
| 10 | 420 |
| 11 | 2520 |
| 12 | 1 |
| 13 | 45 |
| 14 | 210 |
| 15 | 1260 |
| 16 | 3150 |
| 17 | 18900 |
| 18 | 113400 |
| 19 | 1 |
| 20 | 66 |
| 21 | 495 |
| 22 | 924 |
| 23 | 2970 |
| 24 | 13860 |
| 25 | 34650 |
| 26 | 83160 |
| 27 | 207900 |
| 28 | 1247400 |
| 29 | 7484400 |
| 30 | 1 |
| 31 | 91 |
| 32 | 1001 |
| 33 | 3003 |
| 34 | 6006 |
| 35 | 45045 |
| 36 | 84084 |
| 37 | 210210 |
| 38 | 270270 |
| 39 | 1261260 |
| 40 | 3153150 |
| 41 | 7567560 |
| 42 | 18918900 |
| 43 | 113513400 |
| 44 | 681080400 |
[1,1,6,1,15,90,1,28,70,420,2520,1,45,210,1260, 3150,18900,113400,1,66,495,924,2970,13860,34650, 83160,207900,1247400,7484400,1,91,1001,3003,6006, 45045,84084,210210,270270,1261260,3153150,7567560, 18918900,113513400,681080400] |