The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 16 |
| 4 | 86 |
| 5 | 626 |
| 6 | 5267 |
| 7 | 50793 |
| 8 | 543279 |
| 9 | 6544805 |
| 10 | 86503762 |
| 11 | 1242678141 |
| 12 | 19259416827 |
| 13 | 321457169151 |
| 14 | 5736414618209 |
| 15 | 108931865485750 |
| 16 | 2191495621647324 |
| 17 | 46604972526167314 |
| 18 | 1043844453093239627 |
| 19 | 24555321244430950299 |
| 20 | 605239630722584461955 |
| 21 | 15600222966916650541099 |
[1,1,3,16,86,626,5267,50793,543279,6544805, 86503762,1242678141,19259416827,321457169151, 5736414618209,108931865485750,2191495621647324, 46604972526167314,1043844453093239627, 24555321244430950299,605239630722584461955, 15600222966916650541099] |