The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 0 |
| 6 | 1 |
| 7 | 4 |
| 8 | 4 |
| 9 | 1 |
| 10 | 0 |
| 11 | 1 |
| 12 | 13 |
| 13 | 44 |
| 14 | 67 |
| 15 | 56 |
| 16 | 28 |
| 17 | 8 |
| 18 | 1 |
| 19 | 0 |
| 20 | 1 |
| 21 | 40 |
| 22 | 360 |
| 23 | 1546 |
| 24 | 4144 |
| 25 | 7896 |
| 26 | 11408 |
| 27 | 12866 |
| 28 | 11440 |
| 29 | 8008 |
| 30 | 4368 |
| 31 | 1820 |
| 32 | 560 |
| 33 | 120 |
| 34 | 16 |
| 35 | 1 |
| 36 | 0 |
| 37 | 1 |
| 38 | 121 |
| 39 | 2680 |
| 40 | 27550 |
| 41 | 180096 |
| 42 | 866432 |
| 43 | 3308736 |
| 44 | 10453960 |
| 45 | 27991600 |
| 46 | 64472200 |
| 47 | 129002640 |
| 48 | 225783740 |
| 49 | 347370800 |
| 50 | 471435000 |
| 51 | 565722640 |
| 52 | 601080385 |
| 53 | 565722720 |
| 54 | 471435600 |
| 55 | 347373600 |
[1,1,0,1,1,0,1,4,4,1,0,1,13,44,67,56,28,8,1,0,1, 40,360,1546,4144,7896,11408,12866,11440,8008,4368, 1820,560,120,16,1,0,1,121,2680,27550,180096, 866432,3308736,10453960,27991600,64472200, 129002640,225783740,347370800,471435000,565722640, 601080385,565722720,471435600,347373600] |